Contains modified versions of the Doom engine, based on the source code released by id Software. These typically add new features to the game for editing or playing, or port the engine to new hardware or operating systems. In the Doom community these are also referred to as "source ports".
Submit only general purpose source ports in this category, or modifications where the main content of the modification is a modified Doom engine. Projects which merely use a modified engine as one part of a larger project with new levels or enhanced monsters should go to the "Modifications and Add-Ons" category instead.