title: Central tendency

text: Unlike the single-center statistics, this multi-center clustering cannot in general be computed in a closed-form expression, and instead must be computed or approximated by an iterative method; one general approach is expectation–maximization algorithms.


title: Central tendency

text: The notion of a "center" as minimizing variation can be generalized in information geometry as a distribution that minimizes divergence (a generalized distance) from a data set. The most common case is maximum likelihood estimation, where the maximum likelihood estimate (MLE) maximizes likelihood (minimizes expected surprisal), which can be interpreted geometrically by using entropy to measure variation: the MLE minimizes cross entropy (equivalently, relative entropy, Kullback–Leibler divergence).


title: Central tendency

text: A simple example of this is for the center of nominal data: instead of using the mode (the only single-valued "center"), one often uses the empirical measure (the frequency distribution divided by the sample size) as a "center". For example, given binary data, say heads or tails, if a data set consists of 2 heads and 1 tails, then the mode is "heads", but the empirical measure is 2/3 heads, 1/3 tails, which minimizes the cross-entropy (total surprisal) from the data set. This perspective is also used in regression analysis, where least squares finds the solution that minimizes the distances from it, and analogously in logistic regression, a maximum likelihood estimate minimizes the surprisal (information distance).


title: Commander Keen

text: Commander Keen is a series of side-scrolling platform video games developed primarily by id Software. The series consists of six main episodes, a "lost" episode, and a final game; all but the final game were originally released for MS-DOS in 1990 and 1991, while the 2001 "Commander Keen" was released for the Game Boy Color. The series follows the eponymous Commander Keen, the secret identity of the eight-year-old genius Billy Blaze, as he defends the Earth and the galaxy from alien threats with his homemade spaceship, rayguns, and pogo stick. The first three episodes were developed by Ideas from the Deep, the precursor to id, and published by Apogee Software as the shareware title "Commander Keen in Invasion of the Vorticons"; the "lost" episode 3.5 "Commander Keen in Keen Dreams" was developed by id and published as a retail title by Softdisk; episodes four and five were released by Apogee as the shareware "Commander Keen in Goodbye, Galaxy"; and the simultaneously developed episode six was published in retail by FormGen as "Commander Keen in Aliens Ate My Babysitter". Ten years later, a homage and sequel to the series was developed by David A. Palmer Productions and published by Activision as "Commander Keen". Another game was announced in 2019 as under development by ZeniMax Online Studios, but was not released.


title: Commander Keen

text: "Invasion of the Vorticons" was the only game developed by Ideas from the Deep, and was based on programmer John Carmack's creation of adaptive tile refresh, a technique that allowed IBM-compatible general-purpose computers to replicate the smooth scrolling of video game consoles such as the Nintendo Entertainment System. The game's success caused designer Tom Hall, programmers John Carmack and John Romero, and artist Adrian Carmack to found id Software. Their obligations to Softdisk, where they had worked during development of the game, led to the creation of "Keen Dreams" as a prototype for the second trilogy of episodes. The final episode was split off during development into a stand-alone retail title, and plans for a third trilogy were cancelled after the success of "Wolfenstein 3D" (1992) and development focus on 3D first-person shooters such as "Doom" (1993). The final "Keen" game ten years later had oversight but little development work from id.


title: Commander Keen

text: Critical reception and the series' legacy has focused on the two main trilogies of episodes, with "Vorticons" having large success as a shareware game and impacting the success of Apogee (now 3D Realms) and its shareware model. The second trilogy sold fewer copies, which was blamed by id and Apogee on its split into two parts, and the 2001 game received mixed reviews. The MS-DOS games have been re-released in several compilation packages, and all but the sixth episode are still sold through modern emulation releases on platforms such as Steam. References to the series have been made by dozens of other games, especially to the Dopefish, an enemy in the fourth episode, which has been termed one of the video game industry's biggest in-jokes. An active modding community has grown around the series, producing editing tools and unofficial sequels.


title: Commander Keen

text: After the release of "Goodbye, Galaxy" and "Aliens Ate My Babysitter" in 1991, id Software planned to make a third set of episodes for the following December, titled "Commander Keen in The Universe is Toast!". Beyond the proposed title and release date, shown in the epilogue of the two games, no design work was completed before the game was cancelled due to the success of id's "Wolfenstein 3D" (1992) and development focus on 3D first-person shooters such as "Doom" (1993). John Carmack noted in 1999, when referencing the project that became the Game Boy Color game, that the original developers of "Keen" were unlikely to ever work together again on another game. On June 9, 2019 at Bethesda's E3 2019 conference for iOS and Android devices, a new game in the series was announced, again titled "Commander Keen". Under development by ZeniMax Online Studios, the mobile game was announced to include tactical strategy elements and have both single-player and multiplayer gameplay, and star Keen's twin son and daughter, Billy and Billie. It was planned for release in the summer of 2019, but no release or further announcements were made, and all references to the game were removed from Bethesda and ZeniMax websites by June 2020.


title: Commander Keen

text: In addition to the initial releases of the games, several compilation releases have been published: the "id Anthology" compilation in 1996, which includes all seven episodes developed by id or Ideas from the Deep; a compilation release by Apogee in 1998 of the five episodes of "Invasion of the Vorticons" and "Goodbye, Galaxy"; and the "3D Realms Anthology" in 2014, which also includes "Vorticons" and "Galaxy". The Apogee-published episodes have also been released for modern computers through a DOS emulator, and sold through Steam since 2007 as the "Commander Keen Complete Pack".


title: Commander Keen

text: All of the games in the "Commander Keen" series are side-scrolling platform video games: the majority of the game features the player-controlled Commander Keen viewed from the side while moving on a two-dimensional plane. The player can move left and right and can jump; in every episode besides "Keen Dreams" they can also use a pogo stick to bounce continuously and jump higher than they can normally with the correct timing. The levels are composed of platforms on which Keen can stand, and some platforms allow Keen to jump up through them from below. Beginning with episode two, "The Earth Explodes", there are also moving platforms as well as switches which extend bridges over gaps in the floor. "Keen Dreams" and later games add fireman's poles that Keen can climb up or down, and with the exception of the 2001 "Commander Keen" also show the platforms viewed from slightly above so as to give a pseudo-3D effect. Throughout the series, once entered, the only way to exit a level is to reach the end, though for "Keen Dreams" and episodes four through six the player can save and return to the middle of a level, rather than only between levels like the other games. In between levels the player travels on a two-dimensional map, viewed from above; from the map the player can enter levels by approaching the entrance. Some levels are optional and can be bypassed, while others are secret and can only be reached by following specific procedures.


title: Commander Keen

text: The episodes all contain a different set of enemies in their levels, which the player must kill, stun, or avoid. These enemies are typically aliens or robots. Levels can also include hazards, such as electricity or spikes; touching a hazard or most enemies causes Keen to lose a life, and the game is ended if all of Keen's lives are lost. "Invasion of the Vorticons" features a raygun that Keen can use ammo for to kill enemies; "Keen Dreams" exchanges this for flower power pellets that temporarily stun enemies when thrown, episodes four through six use a stun gun that permanently stuns enemies, and the 2001 "Commander Keen" has a stun gun that temporarily stuns enemies unless they are then killed with a pogo jump. The player can also find food items throughout the levels which grant points, with an extra life awarded with enough points. There are also colored keycards which grant access to locked parts of levels, collectable items that award an extra life beginning with episode four, and items that grant an instant extra life.


title: Commander Keen

text: In the first episode, "Marooned on Mars", eight-year-old Billy Blaze, a child genius, builds a spaceship (the "Beans with Bacon Megarocket") and puts on his older brother's football helmet to become Commander Keen. One night while his parents are out of the house he flies to Mars to explore; while away from the ship the Vorticons steal four vital components and hide them in Martian cities. Keen journeys through Martian cities and outposts to find the components, despite the efforts of Martians and robots; the final component is guarded by a Vorticon. Keen returns to Earth—discovering a Vorticon mothership in orbit—and beats his parents home. In "The Earth Explodes" he travels through the mothership and disables its weapons, at the end discovering that the Vorticons are being mind-controlled by the mysterious Grand Intellect, who is actually behind the attack on Earth. In "Keen Must Die" he fights through the cities and outposts of the Vorticon home planet to reach the Grand Intellect, who is revealed to be his school rival Mortimer McMire, who he then defeats.


title: Commander Keen

text: In "Keen Dreams", which is set outside of the main continuity, Keen falls asleep after dinner and wakes up in his pajamas in bed on top of a hill. After being told by potato soldiers that he is now the slave of King Boobus Toober, and being asked by another child to save them, he journeys through the vegetable-themed land to defeat the King, waking up in his bed at home afterwards.


title: Commander Keen

text: The main series of games continues in "Secret of the Oracle", where Keen builds a faster-than-light radio and overhears plans by a race of aliens known as the Shikadi to destroy the galaxy. He flies off to the Oracle on the planet of Gnosticus IV, only to discover that the Gnosticenes that run the Oracle have been kidnapped by the Shikadi. Keen fights through the outposts and temples of the Shadowlands, rescuing the Gnosticenes, and the Oracle then tells Keen that the Shikadi are "shadow beings from the far side of the galaxy" who are building an Armageddon Machine at Korath III to blow up the galaxy and rebuild it as they wish afterwards.


title: Commander Keen

text: In "The Armageddon Machine", Keen infiltrates the titular space station to disable it, destroying the subsystems of the machine located in each level. When he finishes, he finds that the "Gannalech" that was leading the Shikadi was the Grand Intellect McMire, who had escaped Keen in "Vorticons" by leaving behind an android in his place. A note left behind for Keen tells him that McMire plans to instead destroy the Universe. "Aliens Ate My Babysitter" is set around the same time, though it is unclear whether it is actually after the events of "Goodbye, Galaxy"; in it, the alien Bloogs of Fribbulus Xax kidnap Keen's babysitter and plan to eat her. Keen finds his way to her, and she reveals that she is McMire's sister, and that McMire was behind her kidnapping as a way to distract Keen while he plotted to destroy the universe. While the planned trilogy that would cover that plot, "The Universe is Toast", was never developed, the Game Boy Color "Commander Keen" has a sub-space anomaly disrupting life on Earth as an effect of a plot by the Bloogs, Shikadi, and Droidicus, led by McMire, to destroy the universe. Keen fights his way through the three races' planets to find the plasma crystals powering the Omegamatic station, only for McMire to escape after taunting Keen a final time.


title: Commander Keen

text: In September 1990, John Carmack, a game programmer for the "Gamer's Edge" video game subscription service and disk magazine at Softdisk in Shreveport, Louisiana, developed a way to create graphics which could smoothly scroll in any direction in a computer game. At the time, IBM-compatible general-purpose computers were not able to replicate the common feat of video game consoles such as the Nintendo Entertainment System, which were capable of redrawing the entire screen fast enough for a side-scrolling video game due to their specialized hardware. Carmack created adaptive tile refresh: a way to slide the majority of the visible screen to the side both horizontally and vertically when the player moved as if it had not changed, and only redraw the newly-visible portions of the screen. Other games had previously redrawn the whole screen in chunks, or like Carmack's earlier games were limited to scrolling in one direction. He discussed the idea with coworker Tom Hall, who encouraged him to demonstrate it by recreating the first level of the recent "Super Mario Bros. 3" on a computer. The pair did so in a single overnight session, with Hall recreating the graphics of the game—replacing the player character of Mario with Dangerous Dave, a character from an eponymous previous Gamer's Edge game—while Carmack optimized the code. The next morning on September 20, the resulting game, "Dangerous Dave in Copyright Infringement", was shown to their other coworker John Romero. Romero recognized Carmack's idea as a major accomplishment: Nintendo was one of the most successful companies in Japan, largely due to the success of their "Mario" franchise, and the ability to replicate the gameplay of the series on a computer could have large implications.


title: Commander Keen

text: Romero felt that the potential of Carmack's idea should not be "wasted" on Softdisk; while the other members of the Gamer's Edge team more or less agreed, he especially felt that their talents in general were wasted on the company, which needed the money their games brought in but in his opinion neither understood nor appreciated video game design as distinct from general software programming. The manager of the team and fellow programmer, Jay Wilbur, recommended that they take the demo to Nintendo itself, to position themselves as capable of building a PC version of "Super Mario Bros." for the company. The group—composed of Carmack, Romero, Hall, and Wilbur, along with Lane Roathe, the editor for Gamer's Edge, decided to build a full demo game for their idea to send to Nintendo. As they lacked the computers to build the project at home, and could not work on it at Softdisk, they "borrowed" their work computers over the weekend, taking them in their cars to a house shared by Carmack, Wilbur, and Roathe, and made a copy of the first level of the game over the next 72 hours. They credited the game to Ideas from the Deep, a name Romero had previously used for some Softdisk projects. The response from Nintendo a few weeks later was not as hoped for, however; while Nintendo was impressed with their efforts, they wanted the "Mario" series to remain exclusive to Nintendo consoles.


title: Commander Keen

text: Around the same time as the group was rejected by Nintendo, Romero was approached by Scott Miller of Apogee Software, who wanted him to publish more levels for his previous "Pyramids of Egypt—"an adventure game where the player navigates mazes while avoiding Egyptian-themed traps and monsters—through Apogee's shareware model. Miller was pioneering a model of game publishing where part of a game would be released for free, with the remainder of the game available for purchase from Apogee. Romero said he could not, as "Pyramids of Egypt" was owned by Softdisk, but that it did not matter as the game he was now working on was much better, and sent Miller the "Mario" demo. Miller was impressed, and the team agreed to create a new game for Apogee before Christmas of 1990—only a few months away—split into three parts to match Apogee's shareware model of giving away the first part for free to attract interest in the whole. Hall suggested a console-style platformer in the vein of "Super Mario Bros.", as they had the technology made for it; he further recommended a science fiction theme, and developed a short introduction that convinced the team to make "Commander Keen in Invasion of the Vorticons".


title: Commander Keen

text: The Ideas from the Deep team could not afford to leave their jobs to work on the game full-time, so they continued to work at Softdisk, spending their time on the Gamer's Edge games during the day and on "Commander Keen" at night and weekends using Softdisk computers. The group split into different roles: Hall became the game designer and creative director, John Carmack and Romero were the programmers, and Wilbur the manager. They invited artist Adrian Carmack from Softdisk to join them late in development, while Roathe was soon removed from the group. Ideas from the Deep spent nearly every waking moment when they were not working at Softdisk from October through December 1990 working on "Commander Keen", with Wilbur forcing them to eat and take breaks.


title: Commander Keen

text: The game's design was largely driven by Tom Hall: Romero and especially John Carmack were focused almost exclusively on the programming; Wilbur was not involved in the game's design; and Adrian Carmack joined late in development and found the project's "cute" art style, till then mostly created by Hall, far-removed from his preferred, darker, style. Hall's personal experiences and philosophies, therefore, strongly impacted the game: Keen's red shoes and Green Bay Packers football helmet were items Hall wore as a child, dead enemies left behind corpses due to his belief that child players should be taught that death had permanent consequences, and enemies were based loosely on his reading of Sigmund Freud's psychological theories, such as that of the id. Other influences on Hall for the game were "Duck Dodgers in the 24½th Century" and other Chuck Jones cartoons, and "The Available Data on the Worp Reaction", a short story about a child constructing a spaceship. Keen's "Bean-with-Bacon" spaceship was taken from a George Carlin skit about using bay leaves as deodorant so as to smell like soup. Keen was intended to be a reflection of Hall as he had wanted to be as a child. The team separated the game from its "Super Mario Bros." roots by adding non-linear exploration and additional mechanics like the pogo stick. A suggestion from Miller that part of the popularity of "Super Mario Bros" was the presence of secrets and hidden areas in the game led Hall to add several secrets, such as an entire hidden level in the first episode, and the "Galactic Alphabet". The level maps were designed using a custom-made program called Tile Editor (TEd), which was first created for "Dangerous Dave" and was used for the entire "Keen" series as well as several other games.


title: Commander Keen

text: As the game neared completion, Miller began to market the game to players. Strongly encouraged by the updates the team was sending him, he began heavily advertising the game in all of the bulletin board systems (BBS) and game magazines he had access to. The game was completed in early December 1990, and on the afternoon of December 14 Miller began uploading the completed first episode to BBSs, with the other two episodes listed as available for purchase as a mailed plastic bag with floppy disks for US$30. After the arrival of the first royalty check from Apogee, the team planned to quit Softdisk and start their own company. When their boss and owner of Softdisk Al Vekovius confronted them on their plans, as well as their use of company resources to develop the game, the team made no secret of their intentions. Vekovius initially proposed a joint venture between the team and Softdisk, which fell apart when the other employees of the firm threatened to quit in response, and after a few weeks of negotiation the team agreed to produce a series of games for Gamer's Edge, one every two months.


title: Commander Keen

text: Ideas from the Deep, now founded as id Software, used some of these games to prototype ideas for their own games, including in late spring of 1991 "Keen Dreams", which they used to develop new systems for their next set of major episodes of the series. They did not initially want to do a "Keen" game for Softdisk, but eventually decided that doing so would let them fulfill their obligations while also helping to improve the next full set of games for Apogee. The team reprised their roles from the first game, and prototyped an increase in graphical quality, a pseudo-3D view rather than a side-on view, ramps rather than solely flat surfaces, support for sound cards, and changes to the design based on player feedback. The game's plot, as a result, was designed to be a standalone game outside of the continuity of the main series, and not a true sequel. Once the game engine and design changes were completed, "Keen Dreams" was completed in less than a month even as the team simultaneously worked on another game.


title: Commander Keen

text: Beginning development in the June 1991, the team again reprised their roles for "Goodbye, Galaxy". Hall had received feedback from parents who did not like that the enemies in "Vorticons" left behind corpses instead of disappearing like in other games; he did not want the violence to have no effects, and so in "Dreams" had replaced the raygun with pellets that temporarily stunned enemies. He was not satisfied with this change, and while considering ways to remove Keen's parents during the introduction for "Goodbye, Galaxy", came up with a stun gun which would leave behind permanently stunned enemies. Additionally, music, which was missing in prior "Keen" games, was added to "Goodbye, Galaxy", composed by Bobby Prince. The game, episodes four though six, was intended to be published as a set named "Goodbye, Galaxy" in the same manner as the first one: released through Apogee, with episode four released for free in order to spur interest in purchasing the other two episodes. By August they had completed a beta version of episode four, "Secret of the Oracle", and Romero sent it off to a fan he had met from Canada, Mark Rein, who had offered to play-test the game. Romero was impressed with the list of bugs that Rein sent back, as well as with his business sense, and proposed bringing him in to the company as a probationary president for six months in order to help expand their business. Within a few weeks of being hired, Rein made a deal to get id into the commercial market: to take the sixth episode and make it a stand-alone game, published as a retail title through FormGen instead of part of a shareware trilogy. Id signed the deal, but Scott Miller of Apogee was dismayed; he felt that not having a full trilogy for the shareware game would hurt sales.


title: Commander Keen

text: Also in August 1991, the team moved from Shreveport to Hall's hometown of Madison, Wisconsin, leaving behind Wilbur, who was unwilling to leave a stable job at Softdisk to fully join in with the startup, but picking up programmer Jason Blochowiak, who was working at the time at Softdisk. There, they worked on "Goodbye, Galaxy", their remaining Softdisk games, and the now standalone "Commander Keen in Aliens Ate My Babysitter" between August and December. Despite being listed numerically as the sixth episode, due to it having a different publisher and schedule "Aliens Ate My Babysitter" was developed after "Secret of the Oracle" but before "The Armageddon Machine"; the fifth episode, however, was created within one month. Another trilogy of episodes, titled "The Universe Is Toast", was planned for December 1992; id worked on it for a couple of weeks, before shifting focus to "Wolfenstein 3D" (1992). Hall proposed reviving the project after "Wolfenstein" was completed, but the team moved on to "Doom" (1993) instead. Id did not return to the series afterwards, instead continuing to focus on 3D first-person shooters.


title: Commander Keen

text: In October 1999 during an online question and answer session, John Carmack, while discussing that the original founders of id Software were unlikely to ever work together on a game again, mentioned that he was considering the idea of making a "Commander Keen" game for the Game Boy Color handheld game console. Activision formally announced at the start of May 2001 that a new "Commander Keen" game had been developed by David A. Palmer Productions, and would be released at the end of the month. An interview the following week with founder David A. Palmer explained that the original idea for the game came from id, who approached Activision to produce it; Activision in turn recommended Palmer as the developer for the project as they had been attempting to get an agreement with id and Activision for several years for his studio to make a Game Boy Color version of several of their games. While Palmer was the developer for the game, id collaborated with the studio, with id having approval over game design elements and artist Adrian Carmack making some tile artwork for the game.


title: Commander Keen

text: "Commander Keen in Invasion of the Vorticons" was an immediate hit for Apogee: the company's previous sales levels had been around US$7,000 per month, but by Christmas "Keen" already had sales of almost US$30,000. Miller described the game as "a little atom bomb" to magazine editors and BBS controllers when asked about it, and recruited his mother and hired his first employee to handle sales and phone calls from interested players. By June 1991, the game was bringing in over US$60,000 per month. Chris Parker of "PC Magazine" later in 1991 referred to the game's release as a "tremendous success". In 2009, Miller estimated the game's lifetime sales as between 50,000 and 60,000 units. A contemporary review by Barry Simon of "PC Magazine" praised the game's graphical capabilities as having a "Nintendo feel", though he termed the graphics as "well drawn" but "not spectacular" in terms of resolution. He noted that the game was very much an arcade game that players would not purchase for "its scintillating plot or ground-breaking originality", but said that all three episodes were very fun to play and that the scrolling graphics set it apart from similar games. A short summary of the trilogy in 1992 by "PC World" termed it "one of the most spectacular games available" and praised the "superb" sound and graphics, and a similar summary in "CQ Amateur Radio" described it as "Nintendo comes to the PC" and the "best action/adventure game" the reviewer had ever seen.


title: Commander Keen

text: After its release in December 1991, "Goodbye, Galaxy" met with sales "about a third" of the original trilogy. Scott Miller of Apogee blamed the falling sales on the lack of a third episode, which he felt undercut the shareware model of the game. Tom Hall has also claimed that the split hurt the sales of the shareware episodes, though he has said that "they still did decently, though". "PC Zone", in its first issue in 1993, quoted shareware distributors as saying "Goodbye, Galaxy" was one of the top shareware sellers of 1992, behind "Wolfenstein 3D". IGN has also referred to the pair of episodes as "Apogee's hottest sellers". Hall has claimed "The Armageddon Machine" as the best "Commander Keen" episode and his favorite. "Aliens Ate My Babysitter" also did not sell as well as hoped for by id, which the team partially blamed on what they felt was terrible box art done by a company that had previously designed packaging for Lipton tea. Despite this, the sales were strong enough that id agreed to use FormGen as a retail publisher for at least two more games. "PC Zone" also stated that the sales of "Aliens" through shareware distributors was one of the highest in the shareware market in 1993.


title: Commander Keen

text: In October 1992, the Shareware Industry Awards gave the "Commander Keen" series the "Best Entertainment Software and Best Overall" award. A review of the entire "Commander Keen" series in 1993 by Sandy Petersen in the first "Eye of the Monitor" column for "Dragon" described the series as action games with "hilarious graphics". Acknowledging its debt to "Super Mario Bros.", he called it, especially "Goodbye, Galaxy", "one of the best games of its type" and praised it for not being "mindlessly hard", instead requiring some thought to play through, and especially for the humor in the graphics and gameplay. According to Steam Spy, as of June 2016 there are approximately 200,000 owners of the 2007 "Commander Keen Complete Pack" on Steam, and approximately 80,000 owners of the "Keen Dreams" release.


title: Commander Keen

text: The 2001 "Commander Keen" received mixed reviews from critics. The graphics were both praised and criticized; reviewers praised the art style and the "bright and colorful" graphics, but disparaged the "busy" backgrounds and lackluster animations as making the game feel "choppy", and complained that the graphical updates did not reflect the ten years since the last releases. The gameplay similarly received mixed opinions; reviewers were split between praising the difficult, "old school" gameplay as a successful adaptation of the originals and dismissing the "aging" gameplay as sound but not comparing well to more recent games. Reviewers concluded that the game was an "acquired taste" best suited for fans of the original series or younger players.


title: Commander Keen

text: Ideas from the Deep's first royalty check from Apogee in January 1991 convinced them that they no longer needed their day jobs at Softdisk but could devote themselves full-time to their own ideas, leading to the founding of id Software in February. In the summer of 1991, id hosted a seminar for game developers with the intention of licensing the "Commander Keen" engine; they did so, forming the spiritual predecessor to both QuakeCon and id's standard of licensing their game engines.


title: Commander Keen

text: One of the enemies created for "Secret of the Oracle", the Dopefish, has since the game's release become one of the video game industry's biggest in-jokes, making cameo appearances in other games. The Dopefish, which Hall describes as "just a stupid green fish", is described in "Secret of the Oracle" as "the second-dumbest creature in the universe". It has appeared in dozens of other games since its initial appearance, as references, images, or the phrase "Dopefish Lives".


title: Commander Keen

text: The Standard Galactic Alphabet, a writing system used to depict alien languages in the galaxy throughout the series, is used for textual signs and directions and was created by Tom Hall beginning with "Invasion of the Vorticons" as a way to pass hidden messages to players. It is a substitution cypher to the Latin alphabet, including the letters A-Z, opening and closing quotation marks, and a full stop. In 2019, it was added to the Under-ConScript Unicode Registry, using the codepoints to , and is included in the GNU Unifont CSUR extension. The Standard Galactic Alphabet also appears in the game "Minecraft" as the script and symbols used for its Enchanting Table.


title: Commander Keen

text: In January 2018, John Romero and Tom Hall stated on Twitter that Billy Blaze is the grandson of "Wolfenstein" protagonist William "B.J." Blazkowicz and the father of Doomguy from "Doom". Commander Keen himself has appeared or has been referenced in many other video games over the years, including "", "Duke Nukem", "Bio Menace" and more recently in "Doom".


title: Commander Keen

text: A number of fan-made "Commander Keen" games have been created since the publication of the original titles, with a fan website, the Public Commander Keen Forum, devoted to their creation, announcement, and discussion. Since the release of utilities to modify the levels and graphics in the original "Keen" series in 2002, more than fifty mods have been made, most of which feature Commander Keen as the protagonist. These mods include "Commander Genius", an engine, released for multiple platforms, which interprets the episodes as a "retro-evolved" game, with re-polished graphics, a multiplayer compatibility, and a level editor, ports and remakes on different platforms, and "The Universe Is Toast!" mod, an unofficial sequel trilogy of games.


title: Commander Keen

text: In January 2013, Tom Hall began development of "Worlds of Wander", a tool for creating platform games, and the following month began a Kickstarter campaign for the tool and associated game, "Secret Spaceship Club", which he described as a spiritual successor to "Commander Keen". The project was unsuccessful in reaching its goal, though Hall said that he planned to continue working on it in his spare time.


title: Hillary Scott

text: Hillary Dawn Scott-Tyrrell (born April 1, 1986) is an American singer and songwriter. She is the co-lead singer of Lady A, previously known as Lady Antebellum, a country music group that was formed in 2006, and is signed to Big Machine Records.


title: Hillary Scott

text: In collaboration with her family, she released the gospel album "Love Remains" in 2016 as a solo artist. The album reached number 7 on the "Billboard" 200.


title: Hillary Scott

text: Scott was born in Nashville, Tennessee, to country music artist Linda Davis and Lang Scott, a musician and entrepreneur. She has a younger sister named Rylee Jean, who was born in 2000. Scott was homeschooled on the road for kindergarten. She attended elementary school and high school at Donelson Christian Academy where she graduated in 2004. She lived with her grandparents during the time her parents were touring for her mother's musical career. After joining her mom on stage for a Christmas show, she was convinced to pursue a music career. Scott decided at age 14 to become a country singer, and her sister, Rylee, is 14 years younger than her; so she has a tattoo of the number 14 in honor of those two things.


title: Hillary Scott

text: After high school Hillary Scott attended Middle Tennessee State University. During her time at MTSU, Scott worked with singer-songwriter Victoria Shaw and earned some publicity, but was unable to secure a contract with a major label. She auditioned for "American Idol" twice, but failed to make it through to the judges round in both cases. Then she met future bandmates Charles Kelley and later, Dave Haywood, in May 2006. She ran into Kelley at a Nashville bar and recognized him from his MySpace page, where she had been listening to his music. She introduced herself to Kelley and complimented him on his music, which led to his deciding that they should get together with Haywood and write songs. The first song they wrote was "All We'd Ever Need". The song was originally written for her to perform; she convinced Kelley it should be a duet, which led to the forming of Lady A, then known as Lady Antebellum. The group first performed together in August 2006 and signed a record deal with Capitol Nashville in 2007. Scott says that being lead singer of Lady A, as opposed to being a solo artist, lessens the pressure on her on stage.


title: Hillary Scott

text: Scott formed the country music group as Lady Antebellum in 2006, with co-lead singer Charles Kelley and backup singer Dave Haywood. They released their debut single, "Love Don't Live Here", on October 2, 2007, it entered "Billboard"'s Hot Country Songs chart that year, peaking at No. 3 in early 2008. Their debut album was released on April 15, 2008, and debuted at No. 1 on the Top Country Albums chart. It consisted of eleven songs, ten of which were either written or co-written by the members of the trio, and was produced by Paul Worley and Victoria Shaw. The trio released their second single, "Lookin' for a Good Time", in mid-2008, it peaked at No. 11 in December of that year. Their third single, "I Run to You", became their first number one hit on the Hot Country Songs chart in July 2009. The album was certified platinum by the RIAA three months later, in October 2009.


title: Hillary Scott

text: In August 2009, the group released "Need You Now" as the lead single off their sophomore album of the same name. The song topped the Hot Country Songs chart for five weeks in late 2009 before peaking at No. 1 and No. 2 on the Adult Contemporary and Hot 100 charts, respectively, in early 2010. "Need You Now" was released on January 26, 2010, and debuted at No. 1 on "Billboard"'s Top 200 Albums chart with first-week sales of almost 481,000 copies. The album consisted of eleven songs, eight of which were co-written by the members of the trio, and showcased production by both the trio and Worley. The next two singles from the album, "American Honey" and "Our Kind of Love", reached No. 1 on the country charts in April 2010 and September 2010, respectively. The album was certified triple platinum by the RIAA in October 2010. Its fourth and final single, "Hello World", peaked at No. 6 on the country charts in April 2011.


title: Hillary Scott

text: In May 2011, they released "Just a Kiss" as the first single from their third studio album, "Own the Night", which was released on September 13, 2011, and became their fifth number one hit. "Just a Kiss" was 2x certified Platinum by the RIAA. It stayed on the Hot 100 for forty-two weeks. The second single "We Owned the Night" also became a number one hit and was certified Gold. The third single "Dancin' Away with My Heart" was also certified Gold and peaked at number two. "Wanted You More" was released as the fourth and final single from the album. It was their first single since "Lookin' For a Good Time" to miss the Top Ten. The band supported the album with their second headlining tour, the "Own the Night Tour" which was also their first arena and world tour.


title: Hillary Scott

text: On October 22, 2012, "On This Winter's Night", the band first Christmas album was released. One of the tracks on the album "A Holly Jolly Christmas" was released to Country radio and AC radio. A music video for the single was made.


title: Hillary Scott

text: Shortly after the release of "On This Winter's Night", the group started working on their fifth studio. "Golden" was released on May 7, 2013. "Downtown" was the album's first single and peaked at number two on Country radio and number one on the US Country Airplay chart. It was certified platinum by the RIAA. The second single was "Goodbye Town". In late 2013, the deluxe edition re-issue of "Golden" was released which included the third single "Compass". "Compass" was met with positive reviews and went number one on the Country Airplay chart. Throughout 2014, the band toured the album on the "Take Me Downtown Tour".


title: Hillary Scott

text: In May 2014, "Bartender" was released as the first single off their sixth studio album. "Bartender" became their third number on the Country Airplay chart and is certified Platinum. "747" was released on September 30, 2014. "Freestyle" and "Long Stretch of Love" are the second and third singles off "747" respectively.


title: Hillary Scott

text: In October 2015, the group appeared on "Good Morning America" to announce that they would be taking some down time after their "Wheels Up Tour" finishes. Throughout 2016 they continued to play some shows together.


title: Hillary Scott

text: In January 2017, they released "You Look Good" which is the lead single off their upcoming seventh studio album "Heart Break". The album was released on June 9, 2017, and will support it on the "You Look Good Tour".


title: Hillary Scott

text: On June 11, 2020, amid the George Floyd protests, the band announced they would rename themselves "Lady A" in order to avoid racist connotations with Civil War history, as the original name was based on the Antebellum South. The band stated on social media that they were "deeply sorry for the hurt this has caused and for anyone who has felt unsafe, unseen or unvalued."


title: Hillary Scott

text: In November 2015, it was reported that Scott was working on a gospel album. On April 22, 2016, she posted a handwritten note online about the project. In the note she expressed her excitement about it, announced the album's title, "Love Remains" and formally introduced "Hillary Scott & the Scott Family". On why making a gospel album she explains, "Well, I wanted to make this album to share more of who I am. These songs, and many like them are the cry of my heart. I have been singing songs like this my whole my life whether it be in church, with family and friends gathered around with guitars on my screened porch, rocking my baby girl to sleep or while holding the hand of a dying loved one." The album features original material penned by Scott as well as gospel standards and was produced by Ricky Skaggs. Scott's parents, Linda Davis and Lang Scott, and younger sister Rylee also appear on the album. The lead single "Thy Will" was released on April 22, 2016.


title: Hillary Scott

text: "Love Remains" debuted at number 7 on the "Billboard" 200. At the 59th Annual Grammy Awards, "Love Remains" won Best Contemporary Christian Album and "Thy Will" won Best Contemporary Christian Music Performance/Song.


title: Hillary Scott

text: Scott's other works include singing background vocals on Luke Bryan's song, "Do I", which fellow Lady A bandmates, Charles Kelley and Dave Haywood, wrote alongside Bryan. The song was released to radio in April 2009 and peaked at No. 2 on "Billboard"'s Hot Country Songs chart in December of that year.


title: Hillary Scott

text: Scott has recorded a duet with Dave Barnes called "Christmas Tonight" and was featured with Kelley and Haywood, as Lady Antebellum, on Maroon 5's "Out of Goodbyes". "Christmas Tonight" was a single off Barnes' 2010 holiday album, "Very Merry Christmas", and peaked at No. 9 on the Adult Contemporary chart on New Year's Day, 2011. "Out of Goodbyes" was included on Maroon 5's 2010 album, "Hands All Over", but was never released as a single.


title: Hillary Scott

text: In addition, Scott has co-written songs for other country artists, including Sara Evans' "A Little Bit Stronger" and Blake Shelton's "Suffocating". "A Little Bit Stronger" featured Scott on harmony vocals and was released in September 2010 as the lead off single to Evans' sixth studio album, "Stronger". The song was widely used in the 2010 film, "Country Strong", and topped the Hot Country Songs chart in May 2011 for two weeks, becoming Scott's first-ever Number One hit recorded by another artist. "Suffocating" was written by Scott with Shelton's ex-wife, Miranda Lambert, and recorded by Shelton for his 2010 EP, "All About Tonight".


title: Hillary Scott

text: Scott appeared on season 4 of "The Voice" as a mentor for "Team Adam Levine". In 2016, she presented Gospel Hour for BBC Radio 2 Country.


title: Hillary Scott

text: Scott married Nashville-based drummer Chris Tyrrell on January 7, 2012. The two first met in college and reconnected when Lady A and fellow country music band Love and Theft, in which Tyrrell was the drummer at the time, both served as opening acts on Tim McGraw's Southern Voice tour in early 2010. They began dating in July 2010. After their relationship began, Tyrrell filled in for Lady A's drummer for a month in August 2010.


title: Hillary Scott

text: When Lady A released "Just a Kiss" in May 2011, Scott hinted that the song was inspired by her relationship with Tyrrell, saying, "We love writing songs from personal experience, and this is definitely one of those songs. There is so much excitement at the beginning of a new relationship ... all the butterflies and that optimistic feeling that this person could be 'the one.' This song is about one of those times when your brain kicks in and tells your heart 'good things are worth waiting for.'" Tyrrell proposed to Scott on July 2, 2011, during a family vacation in east Tennessee, and the couple wed in upstate New York on January 7, 2012. No wedding date had been announced, and on January 8, the couple posted a video on Lady A's website announcing that they were married. In October 2011, Tyrrell became a full-time member of the band as their new drummer.


title: Hillary Scott

text: Scott has two tattoos, a music note on her right foot and the number 14 on her right wrist. The 14 has two meanings. It represents the age at which she decided music is what she wanted to do for a living and the age difference between her and her younger sister Rylee Jean Scott.


title: Hillary Scott

text: In August 2012, Scott and Tyrrell purchased their first home together, a , 6-bedroom and 8-bathroom home with a pool in Brentwood, Tennessee. Scott announced on December 7, 2012, that she and her husband were expecting their first child. In an interview with Broadway's Electric Barnyard, Scott said that the baby's heartbeat might be heard in the group's latest album, "Golden". On July 22, 2013, she gave birth to her daughter, Eisele Kaye, in Nashville, Tennessee. In 2015, she miscarried her second child, which inspired her single "Thy Will" on the album "Love Remains". Scott's and Tyrell's twin daughters, Betsy Mack and Emory JoAnn, were born on January 29, 2018.


title: Hillary Scott

text: Since 2008, Scott and Lady A have been awarded many top awards in the music industry. Some of the top accolades include nine Grammy awards, seven ACM awards, six CMA awards, one Billboard Music Award and CMT Artists of the Year honorees in 2010 and 2011 and 2018. Scott was also named SESAC songwriter of the year in 2008, 2010, and 2011. In 2011, her publishing company, Hillary Dawn Songs, shared publisher of the year with EMI Foray Music at the SESAC awards. She also has three Academy of Country Music awards, as producer of the album "Need You Now", as producer of the single "Need You Now", and as songwriter for "Need You Now".


title: Giant-impact hypothesis

text: The giant-impact hypothesis, sometimes called the Big Splash, or the Theia Impact, suggests that the Moon formed from the ejecta of a collision between the proto-Earth and a Mars-sized planet, approximately 4.5 billion years ago, in the Hadean eon (about 20 to 100 million years after the Solar System coalesced). The colliding body is sometimes called Theia, from the name of the mythical Greek Titan who was the mother of Selene, the goddess of the Moon. Analysis of lunar rocks, published in a 2016 report, suggests that the impact might have been a direct hit, causing a thorough mixing of both parent bodies.


title: Giant-impact hypothesis

text: The giant-impact hypothesis is currently the favored scientific hypothesis for the formation of the Moon. Supporting evidence includes:


title: Giant-impact hypothesis

text: However, there remain several questions concerning the best current models of the giant-impact hypothesis. The energy of such a giant impact is predicted to have heated Earth to produce a global magma ocean, and evidence of the resultant planetary differentiation of the heavier material sinking into Earth's mantle has been documented. However, there is no self-consistent model that starts with the giant-impact event and follows the evolution of the debris into a single moon. Other remaining questions include when the Moon lost its share of volatile elements and why Venuswhich experienced giant impacts during its formationdoes not host a similar moon.


title: Giant-impact hypothesis

text: In 1898, George Darwin made the suggestion that Earth and the Moon were once a single body. Darwin's hypothesis was that a molten Moon had been spun from Earth because of centrifugal forces, and this became the dominant academic explanation. Using Newtonian mechanics, he calculated that the Moon had orbited much more closely in the past and was drifting away from Earth. This drifting was later confirmed by American and Soviet experiments, using laser ranging targets placed on the Moon.


title: Giant-impact hypothesis

text: Nonetheless, Darwin's calculations could not resolve the mechanics required to trace the Moon back to the surface of Earth. In 1946, Reginald Aldworth Daly of Harvard University challenged Darwin's explanation, adjusting it to postulate that the creation of the Moon was caused by an impact rather than centrifugal forces. Little attention was paid to Professor Daly's challenge until a conference on satellites in 1974, during which the idea was reintroduced and later published and discussed in "Icarus" in 1969 by Drs. William K. Hartmann and Donald R. Davis. Their models suggested that, at the end of the planet formation period, several satellite-sized bodies had formed that could collide with the planets or be captured. They proposed that one of these objects might have collided with Earth, ejecting refractory, volatile-poor dust that could coalesce to form the Moon. This collision could potentially explain the unique geological and geochemical properties of the Moon.


title: Giant-impact hypothesis

text: A similar approach was taken by Canadian astronomer Alastair G. W. Cameron and American astronomer William R. Ward, who suggested that the Moon was formed by the tangential impact upon Earth of a body the size of Mars. It is hypothesized that most of the outer silicates of the colliding body would be vaporized, whereas a metallic core would not. Hence, most of the collisional material sent into orbit would consist of silicates, leaving the coalescing Moon deficient in iron. The more volatile materials that were emitted during the collision probably would escape the Solar System, whereas silicates would tend to coalesce.


title: Giant-impact hypothesis

text: Eighteen months prior to an October 1969 conference on lunar origins, Bill Hartmann, Roger Phillips, and Jeff Taylor challenged fellow lunar scientists: "You have eighteen months. Go back to your Apollo data, go back to your computer, and do whatever you have to, but make up your mind. Don't come to our conference unless you have something to say about the Moon's birth." At the 1969 conference at Kona, Hawaii, the giant-impact hypothesis emerged as the most favored hypothesis.


title: Giant-impact hypothesis

text: The name of the hypothesised protoplanet is derived from the mythical Greek titan Theia , who gave birth to the Moon goddess Selene. This designation was proposed initially by the English geochemist Alex N. Halliday in 2000 and has become accepted in the scientific community. According to modern theories of planet formation, Theia was part of a population of Mars-sized bodies that existed in the Solar System 4.5 billion years ago. One of the attractive features of the giant-impact hypothesis is that the formation of the Moon and Earth align; during the course of its formation, Earth is thought to have experienced dozens of collisions with planet-sized bodies. The Moon-forming collision would have been only one such "giant impact" but certainly the last significant impactor event. The Late Heavy Bombardment by much smaller asteroids occurred laterapproximately 3.9 billion years ago.


title: Giant-impact hypothesis

text: Astronomers think the collision between Earth and Theia happened at about 4.4 to 4.45 bya; about 0.1 billion years after the Solar System began to form. In astronomical terms, the impact would have been of moderate velocity. Theia is thought to have struck Earth at an oblique angle when Earth was nearly fully formed. Computer simulations of this "late-impact" scenario suggest an initial impactor velocity at "infinity" (far enough that gravitational attraction is not a factor) below , increasing as it approached to over at impact, and an impact angle of about 45°. However, oxygen isotope abundance in lunar rock suggests "vigorous mixing" of Theia and Earth, indicating a steep impact angle. Theia's iron core would have sunk into the young Earth's core, and most of Theia's mantle accreted onto Earth's mantle. However, a significant portion of the mantle material from both Theia and Earth would have been ejected into orbit around Earth (if ejected with velocities between orbital velocity and escape velocity) or into individual orbits around the Sun (if ejected at higher velocities).


title: Giant-impact hypothesis

text: Modelling has hypothesised that material in orbit around Earth may have accreted to form the Moon in three consecutive phases; accreting first from the bodies initially present outside Earth's Roche limit, which acted to confine the inner disk material within the Roche limit. The inner disk slowly and viscously spread back out to Earth's Roche limit, pushing along outer bodies via resonant interactions. After several tens of years, the disk spread beyond the Roche limit, and started producing new objects that continued the growth of the Moon, until the inner disk was depleted in mass after several hundreds of years. Material in stable Kepler orbits was thus likely to hit the Earth–Moon system sometime later (because the Earth–Moon system's Kepler orbit around the Sun also remains stable). Estimates based on computer simulations of such an event suggest that some twenty percent of the original mass of Theia would have ended up as an orbiting ring of debris around Earth, and about half of this matter coalesced into the Moon. Earth would have gained significant amounts of angular momentum and mass from such a collision. Regardless of the speed and tilt of Earth's rotation before the impact, it would have experienced a day some five hours long after the impact, and Earth's equator and the Moon's orbit would have become coplanar.


title: Giant-impact hypothesis

text: Not all of the ring material need have been swept up right away: the thickened crust of the Moon's far side suggests the possibility that a second moon about in diameter formed in a Lagrange point of the Moon. The smaller moon may have remained in orbit for tens of millions of years. As the two moons migrated outward from Earth, solar tidal effects would have made the Lagrange orbit unstable, resulting in a slow-velocity collision that "pancaked" the smaller moon onto what is now the far side of the Moon, adding material to its crust.


title: Giant-impact hypothesis

text: Lunar magma cannot pierce through the thick crust of the far side, causing fewer lunar maria, while the near side has a thin crust displaying the large maria visible from Earth.


title: Giant-impact hypothesis

text: Above a high resolution threshold for simulations, a study published in 2022 finds that giant impacts can immediately place a satellite with similar mass and iron content to the Moon into orbit far outside Earth's Roche limit. Even satellites that initially pass within the Roche limit can reliably and predictably survive, by being partially stripped and then torqued onto wider, stable orbits. Furthermore, the outer layers of these directly formed satellites are molten over cooler interiors and are composed of around 60% proto-Earth material. This could alleviate the tension between the Moon's Earth-like isotopic composition and the different signature expected for the impactor. Immediate formation opens up new options for the Moon's early orbit and evolution, including the possibility of a highly tilted orbit to explain the lunar inclination, and offers a simpler, single-stage scenario for the origin of the Moon.


title: Giant-impact hypothesis

text: In 2001, a team at the Carnegie Institution of Washington reported that the rocks from the Apollo program carried an isotopic signature that was identical with rocks from Earth, and were different from almost all other bodies in the Solar System.


title: Giant-impact hypothesis

text: In 2014, a team in Germany reported that the Apollo samples had a slightly different isotopic signature from Earth rocks. The difference was slight, but statistically significant. One possible explanation is that Theia formed near Earth.


title: Giant-impact hypothesis

text: This empirical data showing close similarity of composition can be explained only by the standard giant-impact hypothesis, as it is extremely unlikely that two bodies prior to collision had such similar composition.


title: Giant-impact hypothesis

text: In 2007, researchers from the California Institute of Technology showed that the likelihood of Theia having an identical isotopic signature as Earth was very small (less than 1 percent). They proposed that in the aftermath of the giant impact, while Earth and the proto-lunar disc were molten and vaporised, the two reservoirs were connected by a common silicate vapor atmosphere and that the Earth–Moon system became homogenised by convective stirring while the system existed in the form of a continuous fluid. Such an "equilibration" between the post-impact Earth and the proto-lunar disc is the only proposed scenario that explains the isotopic similarities of the Apollo rocks with rocks from Earth's interior. For this scenario to be viable, however, the proto-lunar disc would have to endure for about 100 years. Work is ongoing to determine whether or not this is possible.


title: Giant-impact hypothesis

text: According to research (2012) to explain similar compositions of Earth and the Moon based on simulations at the University of Bern by physicist Andreas Reufer and his colleagues, Theia collided directly with Earth instead of barely swiping it. The collision speed may have been higher than originally assumed, and this higher velocity may have totally destroyed Theia. According to this modification, the composition of Theia is not so restricted, making a composition of up to 50% water ice possible.


title: Giant-impact hypothesis

text: One effort, in 2018, to homogenise the products of the collision was to energise the primary body by way of a greater pre-collision rotational speed. This way, more material from the primary body would be spun off to form the Moon. Further computer modelling determined that the observed result could be obtained by having the pre-Earth body spinning very rapidly, so much so that it formed a new celestial object which was given the name 'synestia'. This is an unstable state that could have been generated by yet another collision to get the rotation spinning fast enough. Further modelling of this transient structure has shown that the primary body spinning as a doughnut-shaped object (the synestia) existed for about a century (a very short time) before it cooled down and gave birth to Earth and the Moon.


title: Giant-impact hypothesis

text: Another model, in 2019, to explain the similarity of Earth and the Moon's compositions posits that shortly after Earth formed, it was covered by a sea of hot magma, while the impacting object was likely made of solid material. Modelling suggests that this would lead to the impact heating the magma much more than solids from the impacting object, leading to more material being ejected from the proto-Earth, so that about 80% of the Moon-forming debris originated from the proto-Earth. Many prior models had suggested 80% of the Moon coming from the impactor.


title: Giant-impact hypothesis

text: Indirect evidence for the giant impact scenario comes from rocks collected during the Apollo Moon landings, which show oxygen isotope ratios nearly identical to those of Earth. The highly anorthositic composition of the lunar crust, as well as the existence of KREEP-rich samples, suggest that a large portion of the Moon once was molten; and a giant impact scenario could easily have supplied the energy needed to form such a magma ocean. Several lines of evidence show that if the Moon has an iron-rich core, it must be a small one. In particular, the mean density, moment of inertia, rotational signature, and magnetic induction response of the Moon all suggest that the radius of its core is less than about 25% the radius of the Moon, in contrast to about 50% for most of the other terrestrial bodies. Appropriate impact conditions satisfying the angular momentum constraints of the Earth–Moon system yield a Moon formed mostly from the mantles of Earth and the impactor, while the core of the impactor accretes to Earth. Earth has the highest density of all the planets in the Solar System; the absorption of the core of the impactor body explains this observation, given the proposed properties of the early Earth and Theia.


title: Giant-impact hypothesis

text: Comparison of the zinc isotopic composition of lunar samples with that of Earth and Mars rocks provides further evidence for the impact hypothesis. Zinc is strongly fractionated when volatilised in planetary rocks, but not during normal igneous processes, so zinc abundance and isotopic composition can distinguish the two geological processes. Moon rocks contain more heavy isotopes of zinc, and overall less zinc, than corresponding igneous Earth or Mars rocks, which is consistent with zinc being depleted from the Moon through evaporation, as expected for the giant impact origin.


title: Giant-impact hypothesis

text: Collisions between ejecta escaping Earth's gravity and asteroids would have left impact heating signatures in stony meteorites; analysis based on assuming the existence of this effect has been used to date the impact event to 4.47 billion years ago, in agreement with the date obtained by other means.


title: Giant-impact hypothesis

text: Warm silica-rich dust and abundant SiO gas, products of high velocity impactsover between rocky bodies, have been detected by the Spitzer Space Telescope around the nearby (29 pc distant) young (~12 My old) star HD 172555 in the Beta Pictoris moving group. A belt of warm dust in a zone between 0.25AU and 2AU from the young star HD 23514 in the Pleiades cluster appears similar to the predicted results of Theia's collision with the embryonic Earth, and has been interpreted as the result of planet-sized objects colliding with each other. A similar belt of warm dust was detected around the star BD+20°307 (HIP 8920, SAO 75016).


title: Giant-impact hypothesis

text: This lunar origin hypothesis has some difficulties that have yet to be resolved. For example, the giant-impact hypothesis implies that a surface magma ocean would have formed following the impact. Yet there is no evidence that Earth ever had such a magma ocean and it is likely there exists material that has never been processed in a magma ocean.


title: Giant-impact hypothesis

text: If the Moon was formed by such an impact, it is possible that other inner planets also may have been subjected to comparable impacts. A moon that formed around Venus by this process would have been unlikely to escape. If such a moon-forming event had occurred there, a possible explanation of why the planet does not have such a moon might be that a second collision occurred that countered the angular momentum from the first impact. Another possibility is that the strong tidal forces from the Sun would tend to destabilise the orbits of moons around close-in planets. For this reason, if Venus's slow rotation rate began early in its history, any satellites larger than a few kilometers in diameter would likely have spiraled inwards and collided with Venus.


title: Giant-impact hypothesis

text: Simulations of the chaotic period of terrestrial planet formation suggest that impacts like those hypothesised to have formed the Moon were common. For typical terrestrial planets with a mass of 0.5 to 1 Earth masses, such an impact typically results in a single moon containing 4% of the host planet's mass. The inclination of the resulting moon's orbit is random, but this tilt affects the subsequent dynamic evolution of the system. For example, some orbits may cause the moon to spiral back into the planet. Likewise, the proximity of the planet to the star will also affect the orbital evolution. The net effect is that it is more likely for impact-generated moons to survive when they orbit more distant terrestrial planets and are aligned with the planetary orbit.


title: Giant-impact hypothesis

text: In 2004, Princeton University mathematician Edward Belbruno and astrophysicist J. Richard Gott III proposed that Theia coalesced at the or Lagrangian point relative to Earth (in about the same orbit and about 60° ahead or behind), similar to a trojan asteroid. Two-dimensional computer models suggest that the stability of Theia's proposed trojan orbit would have been affected when its growing mass exceeded a threshold of approximately 10% of Earth's mass (the mass of Mars). In this scenario, gravitational perturbations by planetesimals caused Theia to depart from its stable Lagrangian location, and subsequent interactions with proto-Earth led to a collision between the two bodies.


title: Giant-impact hypothesis

text: In 2008, evidence was presented that suggests that the collision might have occurred later than the accepted value of 4.53 Gya, at approximately 4.48 Gya. A 2014 comparison of computer simulations with elemental abundance measurements in Earth's mantle indicated that the collision occurred approximately 95 My after the formation of the Solar System.


title: Giant-impact hypothesis

text: It has been suggested that other significant objects might have been created by the impact, which could have remained in orbit between Earth and the Moon, stuck in Lagrangian points. Such objects might have stayed within the Earth–Moon system for as long as 100 million years, until the gravitational tugs of other planets destabilised the system enough to free the objects. A study published in 2011 suggested that a subsequent collision between the Moon and one of these smaller bodies caused the notable differences in physical characteristics between the two hemispheres of the Moon. This collision, simulations have supported, would have been at a low enough velocity so as not to form a crater; instead, the material from the smaller body would have spread out across the Moon (in what would become its far side), adding a thick layer of highlands crust. The resulting mass irregularities would subsequently produce a gravity gradient that resulted in tidal locking of the Moon so that today, only the near side remains visible from Earth. However, mapping by the GRAIL mission has ruled out this scenario.


title: Giant-impact hypothesis

text: In 2019, a team at the University of Münster reported that the molybdenum isotopic composition in Earth's primitive mantle originates from the outer Solar System, hinting at the source of water on Earth. One possible explanation is that Theia originated in the outer Solar System.


title: Giant-impact hypothesis

text: Other mechanisms that have been suggested at various times for the Moon's origin are that the Moon was spun off from Earth's molten surface by centrifugal force; that it was formed elsewhere and was subsequently captured by Earth's gravitational field; or that Earth and the Moon formed at the same time and place from the same accretion disk. None of these hypotheses can account for the high angular momentum of the Earth–Moon system.


title: Giant-impact hypothesis

text: Another hypothesis attributes the formation of the Moon to the impact of a large asteroid with Earth much later than previously thought, creating the satellite primarily from debris from Earth. In this hypothesis, the formation of the Moon occurs 60–140 million years after the formation of the Solar System. Previously, the age of the Moon had been thought to be 4.527 ± 0.010 billion years. The impact in this scenario would have created a magma ocean on Earth and the proto-Moon with both bodies sharing a common plasma metal vapor atmosphere. The shared metal vapor bridge would have allowed material from Earth and the proto-Moon to exchange and equilibrate into a more common composition.


title: Giant-impact hypothesis

text: Yet another hypothesis proposes that the Moon and Earth formed together instead of separately like the giant-impact hypothesis suggests. This model, published in 2012 by Robin M. Canup, suggests that the Moon and Earth formed from a massive collision of two planetary bodies, each larger than Mars, which then re-collided to form what is now called Earth. After the re-collision, Earth was surrounded by a disk of material, which accreted to form the Moon. This hypothesis could explain evidence that others do not.


title: MIME

text: Multipurpose Internet Mail Extensions (MIME) is an Internet standard that extends the format of email messages to support text in character sets other than ASCII, as well as attachments of audio, video, images, and application programs. Message bodies may consist of multiple parts, and header information may be specified in non-ASCII character sets. Email messages with MIME formatting are typically transmitted with standard protocols, such as the Simple Mail Transfer Protocol (SMTP), the Post Office Protocol (POP), and the Internet Message Access Protocol (IMAP).


title: MIME

text: Although the MIME formalism was designed mainly for SMTP, its content types are also important in other communication protocols. In the HyperText Transfer Protocol (HTTP) for the World Wide Web, servers insert a MIME header field at the beginning of any Web transmission. Clients use the content type or media type header to select an appropriate viewer application for the type of data indicated.


title: MIME

text: MIME originated from the Andrew Messaging System, which was part of Andrew Project developed at Carnegie Mellon University (CMU), as a cross-platform alternative to the Andrew-specific data format.


title: MIME

text: The presence of this header field indicates the message is MIME-formatted. The value is typically "1.0". The field appears as follows:


title: MIME

text: According to MIME co-creator Nathaniel Borenstein, the version number was introduced to permit changes to the MIME protocol in subsequent versions. However, Borenstein admitted short-comings in the specification that hindered the implementation of this feature: ""We did not adequately specify how to handle a future MIME version. ... So if you write something that knows 1.0, what should you do if you encounter 2.0 or 1.1? I sort of thought it was obvious but it turned out everyone implemented that in different ways. And the result is that it would be just about impossible for the Internet to ever define a 2.0 or a 1.1.""


title: MIME

text: This header field indicates the media type of the message content, consisting of a "type" and "subtype", for example


title: MIME

text: Through the use of the "multipart" type, MIME allows mail messages to have parts arranged in a tree structure where the leaf nodes are any non-multipart content type and the non-leaf nodes are any of a variety of multipart types.


title: MIME

text: The original MIME specifications only described the structure of mail messages. They did not address the issue of presentation styles. The content-disposition header field was added in RFC 2183 to specify the presentation style. A MIME part can have:


title: MIME

text: In addition to the presentation style, the field "Content-Disposition" also provides parameters for specifying the name of the file, the creation date and modification date, which can be used by the reader's mail user agent to store the attachment.


title: MIME

text: As of 2010, a majority of mail user agents did not follow this prescription fully. The widely used Mozilla Thunderbird mail client ignores the "content-disposition" fields in the messages and uses independent algorithms for selecting the MIME parts to display automatically. Thunderbird prior to version 3 also sends out newly composed messages with "inline" content disposition for all MIME parts. Most users are unaware of how to set the content disposition to "attachment". Many mail user agents also send messages with the file name in the "name" parameter of the "content-type" header instead of the "filename" parameter of the header field "Content-Disposition". This practice is discouraged, as the file name should be specified either with the parameter "filename", or with both the parameters "filename" and "name".


title: MIME

text: In HTTP, the response header field "Content-Disposition: attachment" is usually used as a hint to the client to present the response body as a downloadable file. Typically, when receiving such a response, a Web browser prompts the user to save its content as a file, instead of displaying it as a page in a browser window, with "filename" suggesting the default file name.


title: MIME

text: In June 1992, MIME (RFC 1341, since made obsolete by RFC 2045) defined a set of methods for representing binary data in formats other than ASCII text format. The "content-transfer-encoding:" MIME header field has 2-sided significance:


title: MIME

text: The RFC and the IANA's list of transfer encodings define the values shown below, which are not case sensitive. Note that '7bit', '8bit', and 'binary' mean that no binary-to-text encoding on top of the original encoding was used. In these cases, the header field is actually redundant for the email client to decode the message body, but it may still be useful as an indicator of what type of object is being sent. Values 'quoted-printable' and 'base64' tell the email client that a binary-to-text encoding scheme was used and that appropriate initial decoding is necessary before the message can be read with its original encoding (e.g. UTF-8).


title: MIME

text: There is no encoding defined which is explicitly designed for sending arbitrary binary data through SMTP transports with the 8BITMIME extension. Thus, if BINARYMIME isn't supported, base64 or quoted-printable (with their associated inefficiency) are sometimes still useful. This restriction does not apply to other uses of MIME such as Web Services with MIME attachments or MTOM.


title: MIME

text: Since RFC 2822, conforming message header field names and values use ASCII characters; values that contain non-ASCII data should use the MIME encoded-word syntax (RFC 2047) instead of a literal string. This syntax uses a string of ASCII characters indicating both the original character encoding (the ""charset"") and the content-transfer-encoding used to map the bytes of the charset into ASCII characters.


title: MIME

text: The ASCII codes for the question mark ("?") and equals sign ("=") may not be represented directly as they are used to delimit the encoded word. The ASCII code for space may not be represented directly because it could cause older parsers to split up the encoded word undesirably. To make the encoding smaller and easier to read the underscore is used to represent the ASCII code for space creating the side effect that underscore cannot be represented directly. The use of encoded words in certain parts of header fields imposes further restrictions on which characters may be represented directly.


title: MIME

text: The encoded-word format is not used for the names of the headers fields (for example "Subject"). These names are usually English terms and always in ASCII in the raw message. When viewing a message with a non-English email client, the header field names might be translated by the client.


title: MIME

text: The MIME multipart message contains a boundary in the header field ; this boundary, which must not occur in any of the parts, is placed between the parts, and at the beginning and end of the body of the message, as follows:


title: MIME

text: Each part consists of its own content header (zero or more header fields) and a body. Multipart content can be nested. The of a multipart type must always be "7bit", "8bit" or "binary" to avoid the complications that would be posed by multiple levels of decoding. The multipart block as a whole does not have a charset; non-ASCII characters in the part headers are handled by the Encoded-Word system, and the part bodies can have charsets specified if appropriate for their content-type.


title: MIME

text: The MIME standard defines various multipart-message subtypes, which specify the nature of the message parts and their relationship to one another. The subtype is specified in the header field of the overall message. For example, a multipart MIME message using the digest subtype would have its set as "multipart/digest".


title: MIME

text: The RFC initially defined four subtypes: mixed, digest, alternative and parallel. A minimally compliant application must support mixed and digest; other subtypes are optional. Applications must treat unrecognized subtypes as "multipart/mixed". Additional subtypes, such as signed and form-data, have since been separately defined in other RFCs.


title: MIME

text: multipart/mixed is used for sending files with different header fields inline (or as attachments). If sending pictures or other easily readable files, most mail clients will display them inline (unless explicitly specified with "Content-Disposition: attachment" in which case offered as attachments). The default content-type for each part is "text/plain".


title: MIME

text: multipart/digest is a simple way to send multiple text messages. The default content-type for each part is "message/rfc822".


title: MIME

text: The multipart/alternative subtype indicates that each part is an "alternative" version of the same (or similar) content, each in a different format denoted by its "Content-Type" header. The order of the parts is significant. RFC1341 states: "In general, user agents that compose multipart/alternative entities should place the body parts in increasing order of preference, that is, with the preferred format last."


title: MIME

text: Systems can then choose the "best" representation they are capable of processing; in general, this will be the last part that the system can understand, although other factors may affect this.


title: MIME

text: Since a client is unlikely to want to send a version that is less faithful than the plain text version, this structure places the plain text version (if present) first. This makes life easier for users of clients that do not understand multipart messages.


title: MIME

text: Most commonly, multipart/alternative is used for email with two parts, one plain text (text/plain) and one HTML (text/html). The plain text part provides backwards compatibility while the HTML part allows use of formatting and hyperlinks. Most email clients offer a user option to prefer plain text over HTML; this is an example of how local factors may affect how an application chooses which "best" part of the message to display.


title: MIME

text: While it is intended that each part of the message represent the same content, the standard does not require this to be enforced in any way. At one time, anti-spam filters would only examine the text/plain part of a message, because it is easier to parse than the text/html part. But spammers eventually took advantage of this, creating messages with an innocuous-looking text/plain part and advertising in the text/html part. Anti-spam software eventually caught up on this trick, penalizing messages with very different text in a multipart/alternative message.


title: MIME

text: A multipart/related is used to indicate that each message part is a component of an aggregate whole. It is for compound objects consisting of several inter-related components proper display cannot be achieved by individually displaying the constituent parts. The message consists of a root part (by default, the first) which reference other parts inline, which may in turn reference other parts. Message parts are commonly referenced by "Content-ID". The syntax of a reference is unspecified and is instead dictated by the encoding or protocol used in the part.


title: MIME

text: One common usage of this subtype is to send a web page complete with images in a single message. The root part would contain the HTML document, and use image tags to reference images stored in the latter parts.


title: MIME

text: "multipart/report" is a message type that contains data formatted for a mail server to read. It is split between a text/plain (or some other content/type easily readable) and a message/delivery-status, which contains the data formatted for the mail server to read.


title: MIME

text: A multipart/signed message is used to attach a digital signature to a message. It has exactly two body parts, a body part and a signature part. The whole of the body part, including mime fields, is used to create the signature part. Many signature types are possible, like "application/pgp-signature" (RFC 3156) and "application/pkcs7-signature" (S/MIME).


title: MIME

text: A multipart/encrypted message has two parts. The first part has control information that is needed to decrypt the application/octet-stream second part. Similar to signed messages, there are different implementations which are


title: MIME

text: The MIME type "multipart/form-data" is used to express values submitted through a form. Originally defined as part of HTML 4.0, it is most commonly used for submitting files with HTTP. It is specified in RFC 7578, superseding RFC 2388. example


title: MIME

text: The content type multipart/x-mixed-replace was developed as part of a technology to emulate server push and streaming over HTTP.


title: MIME

text: All parts of a mixed-replace message have the same semantic meaning. However, each part invalidates "replaces" the previous parts as soon as it is received completely. Clients should process the individual parts as soon as they arrive and should not wait for the whole message to finish.


title: MIME

text: Originally developed by Netscape, it is still supported by Mozilla, Firefox, Safari, and Opera. It is commonly used in IP cameras as the MIME type for MJPEG streams. It was supported by Chrome for main resources until 2013 (images can still be displayed using this content type).


title: MIME

text: The multipart/byterange is used to represent noncontiguous byte ranges of a single message, it is used by HTTP when a server returns multiple byte ranges and is defined in RFC 2616.


title: Port Louis

text: Port Louis (; or , ) is the capital city of Mauritius. It is mainly located in the Port Louis District, with a small western part in the Black River District. Port Louis is the country's economic, cultural and political centre, and most populous city. It is administered by the Municipal City Council of Port Louis. According to the 2012 census conducted by Statistics Mauritius, the population was 147,066.


title: Port Louis

text: Port Louis was used as a harbour by the Dutch settlers from 1606, when they started to refer to the area as "Harbour of Tortoises". In 1736, under French government, it became the administrative centre of Mauritius and a major reprovisioning halt for French ships during their passage between Asia and Europe, around the Cape of Good Hope.


title: Port Louis

text: The Port is named in honour of King Louis XV. During this period of French colonization, Mauritius was known as Ile de France. The French governor at that time, Bertrand-François Mahé de La Bourdonnais, contributed to the development of the city. Since Port Louis was relatively well-protected from strong winds during cyclones by the Moka Mountain Range, Port Louis was selected to house both the main harbor and fort for the island. Value of the port continued during the British occupation of the island during the Napoleonic Wars (1800–15), and helped Britain control the Indian Ocean. However, port calls of ships fell drastically following the opening of the Suez Canal in 1869. Activity in the port increased during the seven-year closure of the Suez Canal (starting in 1967). Modernization of the port in the late 1970s has helped it maintain its role as the central point for all imports and exports from Mauritius. While Port Louis continues to be the business and administrative capital of Mauritius, expansion of the tourism industry in the late 1990s led to considerable development in Port Louis, with many shops, hotels, and restaurants being built in the Caudan Waterfront area.


title: Port Louis

text: Raouf Oderuth, the Mauritian Artist provides a 1930s scene depicting the waterfront when motorised transportation hardly existed. Place D’Armes is still recognisable despite high rise buildings, heavy traffic jam and huge crowds of people.


title: Port Louis

text: Local governance of Port Louis is overseen by a municipal council. The City Council of Port Louis was first established in 1830 and is currently one of five municipal councils responsible for the urban areas in Mauritius, as organized under Local Government Act 2011. Twenty-four councillors are elected democratically to administer the council. Councillors then elect a Lord Mayor and a Deputy Lord Mayor. Functions of the council are performed through Departments of Administration, Finance, Land Use and Planning, Public Infrastructure, Public Health, Welfare, Parks and Gardens, and City Library. Services delivered by the local government include pre-school, kindergarten, and vocational schools, health protection, housing regulation, some road services, refuse collection, cemeteries, some environmental and consumer protection services, and economic promotion activities. Other services are provided to the city by the central government. These include police services through the Mauritius Police Force, which maintains two divisions responsible for the Port Louis area (Metropolitan Divisions North and South). There is also a specific Port Police, composed of the Harbour Police and Bulk Sugar Terminal Police. Their roles include providing security to cargo and facilities in the port area and enforcing laws related to harbour regulations, customs, quarantine, immigration, and drug trafficking.


title: Port Louis

text: Owing to its location in the rain shadow of the southeast trade winds, Port Louis features a hot semi-arid climate ("BSh") under Köppen's climate classification. Its wettest months are from December through April where on average (or more) of rain fall. The remaining months form Port Louis' dry season. The city also shows a noticeable but small range of average temperatures. Port Louis' coolest temperatures are seen mid-year where average high temperatures are around . During the height of the wet season, the city sees its highest temperatures where average high temperatures are usually around .


title: Port Louis

text: The economy of the city is mostly dominated by its financial centre, port facilities, tourism and the manufacturing sector which include textiles, chemicals, plastics and pharmaceuticals. Port Louis is home to the biggest port facility in the Indian Ocean region and one of Africa's major financial centres.


title: Port Louis

text: Port Louis is home to the nation's main harbor, which is the only official port of entry and exit for sea vessels in Mauritius. Ships must be cleared in the port before visiting any other anchorage in the island nation.


title: Port Louis

text: The Mauritius Ports Authority (MPA), established by law in 1998, is the port authority responsible for Port Louis. The MPA provides port infrastructure, enters into contracts with private providers for port and cargo-handling services, promotes the use and development of the ports, and licenses and regulates port and marine services. The harbor adjoins the main city, with the port currently comprising three terminals. Terminal I contains a total of 1180 meters of quay, with six berthing positions for cargo, passengers, and fishing boats. Terminal II contains 986 meters of quays with six berthing positions, and includes specialized facilities for handling and storing sugar, fish, tallow, and caustic soda. In particular, the Bulk Sugar Terminal (operated by the Mauritius Sugar Terminal Corporation) can handle vessels with up to 11 meters of draft, can load sugar at a rate of 1450 tons per hour, and can store 175,000 tons of cargo. Also present in Terminal II is a dedicated 124-meter cruise ship jetty, with a dredged depth of 10.8 metres. Terminal III has two 280-meter quays with a depth of 14 meters, and is specialized for handling container ships, having three super-post-Panamax and five post-Panamax gantry cranes. Also present are storage facilities for bulk ethanol and tie-in points for reefer containers. Vessels too large to dock at the quays can anchor at the Outer Anchorage, which is still within the official boundaries of the port.


title: Port Louis

text: The number of ships visiting the port numbered at over 2,200 annually in 2010. In 2019, cargo container capacity was 1 million TEUs (twenty-foot equivalent units). Overall, the port contributes 2% to the country's GDP.


title: Port Louis

text: The cruise ship terminal, opened in 2010 and named after Christian Decotter (past chairman of the Mauritius Tourism Advisory Board), illustrates the increasing role of tourism in the economy of Mauritius. Cruise ships of up to 300 metres can be accommodated at the facility, which includes two access bridges for passengers and vehicles. The facility was the first in the Indian Ocean to be capable of handling the largest cruise ships in the world. In 2012, passenger arrivals by sea included 11,510 tourists and 6,450 excursionists who arrived aboard 23 cruise ships.


title: Port Louis

text: Berthing facilities are available at the Caudan Waterfront. Available are 20 berths with electrical and water connections, showers and toilets, laundry, and vehicle parking. Also available are dry dock and hull and sail repair facilities. Depths of the berths range from 2 to 4 meters, depending on the tide, and up to 30-meter ships can be accommodated.


title: Port Louis

text: Port Louis is the financial centre of Mauritius, which has established itself as safe and trusted location for conducting business due to its strong democracy, political stability, and multilingual population. Located in Port Louis is the Stock Exchange of Mauritius. Also in Port Louis are over ten commercial banks that serve both domestic and offshore clients, insurance companies, pension funds, mutual funds, leasing companies, and foreign exchange dealers. The oldest bank based in Port Louis is the Mauritius Commercial Bank, which was founded in 1838. The Bank of Mauritius is the central bank of the country. Measuring from ground level to its pinnacle, the Bank of Mauritius Tower is the tallest building in the country.


title: Port Louis

text: Port Louis is served by two major bus stations. Victoria Station is used by buses to and from the eastern and southern areas and the Plaines Wilhems district. Immigration Square, also known as Gare du Nord, is a terminus for buses coming from the northern districts of Pamplemousses and Rivière du Rempart. A number of inter-city buses carry passengers to and from nearby suburbs such as Plaine Verte, Vallée-des-Prêtres, Pailles, Plaine Lauzun and Cite Vallijee.


title: Port Louis

text: Most streets in Port Louis are laid out in rectangular grids, and many are one-way. Although most roads are in good shape, many streets are fairly narrow as would be expected for a historic colonial town. Due to the daily influx of workers to business and government offices in Port Louis, day-time traffic can be quite heavy and finding parking spaces a challenge. To cope with increasing traffic congestion, the government has proposed a light rail transit system. Other suggestions have included moving some of the 24 government ministries currently located in Port Louis to surrounding regions, or introducing flexible work schedules. An effort to move workers from the city centre has already started with the construction of the Ebène office tower complex south of Port Louis. A ring road passing on the east side of Port Louis is also expected to reduce congestion. Phase 1 of that project was completed in 2013, but in February 2014 the road needed to be closed due to the appearance of a major crack, apparently due to faulty design. Another project initiated to reduce congestion is the construction of a bridge (commonly referred to as the "Dream Bridge") from Les Salines to Roche-Bois, which will span the Port Louis harbor.


title: Port Louis

text: In 2012, the government decided to construct an approximately 25-km rail system between Curepipe and Port Louis, which had been under consideration for nearly three decades. The project was initiated by a government-to-government agreement with the Singapore Cooperation Enterprise (SCE), along with private partners Singapore Mass Rapid Transit (SMRT) Corporation and the South African/Australian engineering firm Aurecon Ltd. The goal was to develop a preliminary plan of the system, and then solicit expressions of interest for a design-build-operate-finance scheme, with a concession period of 33 years. As of May 2014 a concession has not yet been awarded. The current plan includes a northern terminus at Port Louis' Victoria Station. This would restore passenger rail service to Port Louis for the first time since March 1956.


title: Port Louis

text: Construction for the light rail transit transport system began in the Fall of 2017, with the government of Mauritius awarding the contract to Mumbai-based design and construction firm of Larsen & Toubro. The first stage of Mauritius Metro Express, from Port Louis to Rose Hill Central, was opened on 10 January 2020. The second stage, to Curepipe, is scheduled to be completed in 2021.


title: Port Louis

text: Primary and secondary schools in Port Louis include state-run and private institutions. Most private schools receive much of their support from the government, based on a formula where the government pays staff wages and operating expenses based on a grant formula. Other costs are covered by students and their families, such as books and uniforms. The government also provides private schools with loans at preferential interest rates to help upgrade facilities. The state-affiliated schools include those operated by MEDCO (Mauritius Educational Development Company), which is a partnership between the Government of Mauritius and the State Investment Corporation.


title: Port Louis

text: Port-Louis houses several secondary schools which includes Alpha College, Bhujoharry College, Labourdonnais College, and Port Louis Academy, Loreto College, Madad Ul Islam Girls College, Muslim Girls College, City College, Full Day School, Institute of Islamic and Secular Studies, London College, Ocep The Open College, and Port Louis High School, MEDCO Trinity Secondary School, MEDCO Trinity Secondary School, Port Louis North SSS, and Sir Abdool Razack Mohammed SSS, Goolam Mohammed Dawjee Atchia State College, MEDCO Cassis Secondary School, Renganaden Seeneevassen SSS, Port Louis SSS and Royal College Port Louis. The state also operates a vocational school for boys, Immaculee Conception SSV.


title: Port Louis

text: The major institute of tertiary education in Port Louis is the University of Technology, Mauritius, a public university with a technology focus. The École de Medecine Louis Pasteur prepares students for medical studies at Universite de Lille in France. Several technical schools also have locations in the city, including the Jhurry Rya School which specializes in information technology, Appavoo Business School, Apollo Bramwell Nursing School, BSP School of Accountancy & Management, and the London College of Accountancy.


title: Port Louis

text: The city is full of numerous buildings and monuments that reflect its rich and diverse colonial history. Near the city centre, there are several French colonial buildings that date to the 18th century, including Government House. Other prominent traditional elements include the Jummah Mosque, the majestic English Saint James Cathedral, the Indian Tamil Temple, the elegant five-tier colonial Port Louis Theatre (Théâtre de Port-Louis), the Champ de Mars Racecourse, and the nearby Chinese Pagoda. Also present are some typical houses from past eras, which are mostly wooden structures with shuttered windows and large porches. However, many historic buildings are in a poor state of repair and are being quickly replaced with homes and commercial structures constructed from more durable but less sustainable materials such as concrete, and the city now includes many glass/concrete high-rises.


title: Port Louis

text: The Pagoda is a central feature of the Port Louis Chinatown, which is one of several Chinatowns in Africa. Its entrance is marked by a large "friendship" gate, just east of the Central Market. The site was the traditional location of homes and shops of the Chinese community, which was dominated by descendants of the Hakka Chinese, who first came to Mauritius in 1826.


title: Port Louis

text: Raouf Oderuth, the Artist provides a glimpse of 1960s Chinatown with some original architectural features and local lifestyle of the past.


title: Port Louis

text: Chinatown is now home to a more diverse community, but preserves its original appearance and contains many small shops and restaurants. Its old buildings and Chinese pagodas face the modern buildings of the city's business centre. The Chinese Chamber of Commerce (founded in 1908 and second only to Singapore as the world's oldest) hosts a popular food and cultural festival each April or May. The Chamber also runs a funeral parlour for the Chinese Community called 'Kit Lok', to provide vigil facilities for bereaved families.


title: Port Louis

text: Port Louis has been an active cultural city attracting painters, poets, sculptors and writers for centuries. Marie-Thérèse Humbert wrote her famous novel, "La Montagne des Signaux", with Port-Louis in mind. Malcolm de Chazal was a common Mauritian visionary writer and painter who was often seen in the capital, mostly at the central market, Champ de Mars and l'hôtel National. Robert Edouard-Hart, a great poet found in this very active city a source of inspiration. Port-Louis born poet and semiologist Khal Torabully, the foremost poet of indenture and coolitude, recently designed Travellers' Lane at the Jardin de la Compagnie, inaugurated by Navin Ramgoolam, the Mauritian Prime Minister and the Parcours Culturel with aphorisms of Malcolm de Chazal, just facing the famous Port Louis Theatre. That theater, still in use and catering mostly to presentations of classical music, jazz, and local drama, has a distinguished history that includes the first presentation of opera on the island in the 19th century by travelling European troupes.