Id Software's lawyers got a little uncomfortable about releasing the Doom 3 source code — a tradition at id — because of a small patent issue, but John Carmack saved the day by just coding around it. We're playing it a little fast and loose here, but the story is that between 1998 and 2000, both Carmack and Creative Labs independently developed a very similar method for rendering shadows in a 3D environment. Although the technique is commonly known as Carmack's Reverse, the patent went to Creative, so the lawyers understandably didn't want to get in trouble for open-sourcing somebody else's technology. However, the problem was apparently minor — according to a tweet from id's founder himself, it was solved by simply adding four lines of code and changing two, a technique we'll lovingly refer to as Carmack's Revenge. If the attorneys are happy with John's modifications, the source code should be released fairly soon. We'll begin work on incorporating it into The Verge as soon as that happens.