Above everything else, Debian developers believe in free software, as defined by the Free Software Foundation. In essence, this definition ensures that users have the freedom to:
- Run the program for any purpose
- Study how the program works and make modifications
- Redistribute copies
- Distribute copies of modified versions
All of this is embodied in the Debian Social Contract, and the Debian Free Software Guidelines (DFSG), both of which may be found at http://www.debian.org/social_contract. All Debian developers commit to this social contract, which states the guiding principles for the Debian Project, and influences all decisions as to what's included in the distribution and how it is distributed and maintained. Of particular note are the provisions for non-free software, and support in many different computing environments.
The non-free provision not only allows for such software to run on Debian systems but provides for special Debian repositories for that software which can be released without payment. Such software is, in fact, supported by Debian developers who package and support it. The primary distinction is that it is not a part of the official Debian distribution, due to licensing restrictions. Of course, software that must be paid for can also be run on Debian distributions. It just can't be included in the Debian repositories.
