The open source invasion began when a group of astute computer software developers at a place called GNU drafted the first open source license, the GNU General Public License. They had felt confined by restrictive licensing agreements that were hampering the ability of users to share computer software. By producing this open source agreement for software users these programmers created a bold new way of copyrighting software. It has produced an innovative working environment for software development by establishing true collaboration among developers and helped merge cooperative intellectual resources. This precedent in software licensing has led to other similar open source licenses being crafted. The assimilation of open licenses into the software industry has created an open source development community that thrives on mutual sharing. The open source invasion has unleashed a new way of thinking about software that empowers all computer users.

This remarkable new openness can just mean good software at low prices that computer users can share freely, but there is more to it. An open source license also requires that a readable version of the software code be packaged with the software and made available to every user. The user can scrutinize the code for problems, upgrade it to meet the user's needs or view it as a learning tool. Even further freedom exists for developers who want to expand on the open source software code. The developer can improve upon the code and then redistribute it, but with certain restrictions regarding the distribution. This open freedom to developers has an even deeper impact to the users of the software.