The source code to Doom 3: BFG Edition has also been released its Doom Classic engine is version 1.11. The source for the Linux port was released publicly-this was released as version 1.10. The 1.3 through 1.6 beta versions of Doom also have partial Doom II support, as the game was in development when those betas were published. In addition to these, there is also a bootleg copy of 1.666 which was leaked prior to the official release of the game, which the upgrade patches are not compatible with, but has no known differences with the official 1.666 release.
The French version of 1.8 has received a full translation. 1.7a only changes the phone number listed on the ENDOOM text screen displayed in DOS after exiting the game. The German version of 1.666 uses a different executable and its copy of DOOM2.WAD omits the MAP31 and MAP32 secret levels. This is a sub-page of Doom II: Hell on Earth (PC).