id Software has just made the source code for Doom 3 public. This comes after the company resolved a legal issue regarding a certain technology in the game's code.
The legal issue revolved around the fact that the code for 'Carmack's Reverse' was not developed by id Software co-founder John Carmack alone. The technology is used to help render shadows in Doom 3. After the issue was resolved, Carmack only needed to add four new lines of code and make changes to two other.
The source code, which can be found here (https://github.com/TTimo/doom3.gpl) does not however include the game as it is protected by the games original End User License Agreement - the original released in 2004.