The program is published under the GNU General Public License Version 3. The Foundations of the GPL is:
Nobody should be restricted by the software they use. There are four freedoms that every user should have:
- the freedom to use the software for any purpose,
- the freedom to change the software to suit your needs,
- the freedom to share the software with your friends and neighbors, and
- the freedom to share the changes you make.
- The program is free of any charge, free of any advertisement and has the complete functionality.
- No user data will be acquired or commercialized in any way.
- Propagation of the program and collaboration in the project is welcome.
The only obligation of the GPL is to grant the same permission even for changes. You are not allowed to modify the license.
Please note that additional files provided by the community my be published under a different license. Have a look at the particular file and ask the author in case of doubt.