Established models and processes for software development try to remedy the prevailing uncoordinated chaos by adopting organisational principles from more traditional engineering disciplines. Their handicap is that they are 'heavyweight' and 'inert', essentially trying to solve problems the ordering customers had years ago, when the project was started and specifications were defined, instead of problems they will have when the software is ready for deployment.

In February of 2001, seventeen representatives of alternative, newer methods like Extreme Programming, SCRUM, DSDM, Adaptive Software Development, Crystal, Feature-Driven Development, Pragmatic Programming, and others sympathetic to the need for an alternative to documentation driven, heavyweight software development processes made up and signed the Manifesto for Agile Software Development. [1] The indented blocks below contain its wording, with some comments by me in between:


Individuals and interactions over processes and tools
The idea here is that no process or tool will turn a bunch of idiots into a highly qualified team. On the other hand, qualified software engineers will organize themselves by the principle of emergence, when there is little management and plenty of communication and interaction. It also doesn't make much sense to write huge books about sequences of operations, responsibilities, standards, methods, tools, etc., because in software engineering, production processes don't repeat themselves and are not uniform, and trying to conduct them that way is definitely not agile.
Working software over comprehensive documentation
Filling dead trees no one's going to look at ever again is a waste of time. Instead, documentation is only created where it is necessary for a safe operation or no better forms of communication can be found.
Customer collaboration over contract negotiation
Responding to change over following a plan
Writing down a full specification of the yet nonexistant software system at the start of the project is not possible in a sensible way. Instead, the customer should be involved in the whole creation process, ensuring the engineers produce what he needs. Plans become obsolete too fast.


Since then, lots of developers signed the manifesto. They follow the following principles [1], which are much like Extreme Programming:




Business people and developers must work together daily throughout the project.



Working software is the primary measure of progress.


Continuous attention to technical excellence and good design enhances agility.

Simplicity---the art of maximizing the amount of work not done---is essential.

