Chocolate Doom

Chocolate Doom, is a source port developed by Simon Howard, who previously developed SMMU. The name "Chocolate Doom" is a pun on "vanilla Doom", to imply that it is as close as possible to the original, unmodified game engine, without the extensions and bugfixes that various source ports introduced. Which is not to say that Chocolate Doom does not offer additional features, rather, its original features merely aim to emulate hardware and software commonly used with Doom in the nineties, such as offering an OPL emulator or special parameters for merging files. Some of the OPL code from Chocolate Doom is used in *ZDoom since GZDoom 3.0, to replace Vladimir Arnost's MUSLIB code that had a cumbersome license.