Doom 3 GPL
Few days ago Timothee “TTimo” Besset published source code of Doom 3. It’s licensed under GPL3 license. No assets were published together with source code, there’s still End User License Agreement (EULA) for them. Release required small changes in code responsible for rendering of shadows, which originally had used Creative’s patented technology. John Carmack says that they had to change only few lines of code:
@turbokater this demonstrates the idiocy of the patent – the workaround added four lines of code and changed two.