The Python Game Book

code games. learn Python.

User Tools

Site Tools




GPL license

The GPL license was created by Richard Stallman for the Emacs editor and is one of the key elements for the success of the GNU/Linux system of free software.

Basically the license give users the right to view, learn from, use, share, and modify the source code, under the condition that the same license apply to all modifications of the source code. This makes sure that free software remain free (“free as in speech”). The license does NOT forbid to make money out of a program, it demands only that the source code must be made public.

You can find the GPL license here:

for game programmers

For game developers, using the gpl license for the source code of a game means that this source code must be made public and can be used, viewed and edited by other people. It is still possible to generate money out of a gpl-licensed game:

  • It is possible to sell the compiled binary 1) versions of a game program as long as the source code 2) is public and can be compiled3)by interested users themselves.
  • It is possible to split the game into the gpl-licensed source code (game engine) and other licensed parts like music, sounds, graphics, level-design and AI modules. Selling it all togehter is possible, as long as the gpl-licensed source code remains free to view, modify, download, share and use. Thus other developers can learn / improve the source code but can not resell the same game without recrceatin / licensing the necessary graphic files etc.
  • It is possible to sell services around a gpl-licensed game, like running a webserver for online tournaments, managing user groups etc.
  • It is of course possible to ask for donations (flattr, paypal button, gifts) for creating a gpl-licensed games, either before or after publishing the game.

full text of gpl license

from the website:





  <one line to give the program's name and a brief idea of what it does.>
  Copyright (C) <year>  <name of author>
  This program is free software: you can redistribute it and/or modify
  it under the terms of the GNU General Public License as published by
  the Free Software Foundation, either version 3 of the License, or
  (at your option) any later version.
  This program is distributed in the hope that it will be useful,
  but WITHOUT ANY WARRANTY; without even the implied warranty of
  GNU General Public License for more details.
  You should have received a copy of the GNU General Public License
  along with this program.  If not, see <>.
  <program>  Copyright (C) <year>  <name of author>
  This program comes with ABSOLUTELY NO WARRANTY; for details type `show w'.
  This is free software, and you are welcome to redistribute it
  under certain conditions; type `show c' for details.



in the case of python programs, this would be the .pyc version that is generated automatic at the first time a python program runs
in the case of python programs, this is the .py file
as python is an interpreted language, the “compiling process” is far less complicated than to compile a c program. Still, when using many thrid party modules and different platforms, users can be convinced to simply pay a small fee to have a ready-to-run application instead of setting up all necessary programs
en/glossary/g/gpl_license.txt · Last modified: 2020/05/13 06:38 by horst