Doom 3 source code free to download

As is id software John Carmack`s good tradition, he made the engine available for public to download and use. If you are into game engines programming and want some reference for your code, go here for the source link:


https://github.com/TTimo/doom3.gpl


All id software open source is now here:
https://github.com/id-Software


Also, old id games are still available for few £ to download here from Steam.