For example, one feature commonly lost is the ability to play back old demos. It is common for source port authors to make fixes and extensions at the expense of compatibility with the original DOS versions. These developments have been important, arguably essential, in maintaining interest in the game, and to this day there remains a reasonably large community of people who continue to create Doom levels and to play them.
Source port authors have worked to extend the Doom engine in impressive ways, and to fix bugs that limited the original DOS versions of Doom. Since the release of the Doom source code in 1998, a number of Doom source ports have been created (there is a comprehensive list on Doomworld). Why do we need yet another source port? Edit Chocolate Doom 'is not Vanilla Doom', but aims to behave similarly to Vanilla Doom. It is also inspired by the GNU tradition of recursive acronyms: for example, 'GNU's Not Unix', but it behaves very similarly to Unix. The name 'Chocolate Doom' is a word play on the term Vanilla Doom, which is commonly used to refer to the original DOS Doom executables. The purpose of Chocolate Doom is to be as compatible as possible with the original DOS version of Doom.
Chocolate Doom is a source port of the game Doom, by id Software.
