Debian // is a computer operating system composed of software packages released as free and open source software especially under the GNU General Public License and other open source licenses. The primary form, Debian GNU/Linux, which uses the Linux kernel and GNU OS tools, is a popular and influential Linux distribution.
It is distributed with access to repositories containing thousands of software packages ready for installation and use. Debian is known for strict adherence to the Unix and free software philosophies as well as using collaborative software development and testing processes.
The Debian Project is governed by the Debian Constitution and the Social Contract which set out the governance structure of the project as well as explicitly stating that the goal of the project is the development of a free operating system.
Thus, the Debian Project is an independent decentralized organization; it is not backed by a company like other Linux distributions such as Ubuntu, openSUSE, Fedora, and Mandriva. The cost of developing all the packages included in Debian 4.0 etch (283 million lines of code), using the COCOMO model, has been estimated to be close to US$13 billion.