The source code is entirely released at no cost under the GNU General Public License, version 3. This guarantees the free and open source nature of the code and of its extensions. In particular:
- modified versions of the code can be freely created and distributed, without restriction, under the condition that the original copyright statement is maintained. These modifications must be redistributed under GNU General Public License version 3 (GPL 3).
- if binary versions of the code are distributed, the corresponding source code must be made available by the distributor.
The documentation of the code is released under the GNU Free Documentation License, version 1.3.