Mark Zuckerberg FacebookFacebook CEO Mark ZuckerbergReuters/Kimberly White

In honor of Facebook's 10-year anniversary, its engineering team posted a timeline of some of the company's milestone engineering inventions.

The truth is, that timeline includes only a small sample of the tech Facebook has invented and, more importantly, given away for free.

Most big cloud companies like Amazon, Google, Microsoft and others invent their own technology to run their own business operations. But unlike those companies, Facebook has an open-source ethic, meaning it almost always gives its tech away to be freely used by others. This, in turn, lets people outside of Facebook add their own tweaks to projects. So Facebook gets the benefit of having lots of people contribute to its tech. (That's how open source works.)

We couldn't begin to list all the technology that Facebook has invented in the last 10 years. Many of it is deeply geeky stuff for writing software or running corporate data centers. But here's a small roundup of some of the most significant pieces:

Facebook created a database called Cassandra.  This is something called a "noSQL database," meaning that it runs on low-cost computer servers and can store all kinds of data. Cassandra is popular and used by companies like Netflix, eBay, Twitter, Reddit, Cisco and others.

Facebook has released dozens of free software development tools like "xctool" for testing iOS apps; "Buck" for writing Android apps; and "Origami" that lets non-programmers use Apple's free animation Mac OS X app, Quartz Composer, for building mobile apps.

Facebook has invented new network hardware that could challenge established players like Cisco. This is a new kind of "network switch" that will be very fast and inexpensive, and is part of a trend called "software-defined networking."

Facebook invented a new way to build computers and other data center hardware called the Open Compute Project (OCP). This project has saved Facebook $1 billion in three years, CEO Mark Zuckerberg said, plus Facebook offers the hardware designs to anyone who wants them, for free.

Here's what what of the OCP servers look like:

Facebook OCP 03Facebook computer "Winterfell"Facebook

Facebook invented something called the "Group Hug Board" where a computer's insides (otherwise known as a motherboard) is converted into a Lego-like assembly project where you can pick all the pieces, even the main processor, and snap them together.

Here's what the Group Hug looks like:

Facebook OCP 05Facebook

Here's a list of the tech that Facebook engineers say they are most proud of building over the last decade.

Facebook's engineering achievements