The Doom 3 source code has been released after initially being delayed by legal issues.
Its release had been stalled after developer John Carmack was advised to re-write some lines of code.
Doom 3 had employed a stencil shadowing technique, knows as “Carmack’s Reverse”, that was co-written yet fully patented by Creative Labs, causing legal issues in regards to making the code open source.
These problems appear to have been settled and the source code can now be downloaded free of charge.
No game data has been includeded in the release.