Doom: The Abyss

DOOM The Abyss, also known as The Abyss, is a 24-map megawad released in September 1995 for Doom II by J.M.P van Waveren (MrElusive) and Miklos de Rijk (H2SO4), co-creators of the Omicron Bot for Quake. As of this writing, The Abyss is their only known Doom work. The Abyss was relatively unknown for years after its release, and was never released in any known compilation, nor mentioned in any Usenet posts. It was rediscovered in the mid-2000s through a crawl of an id Software public staff server. The majority of the maps are non-linear "dungeons" which rely on secret passageways and switch puzzles, and have multiple paths that the player can take to complete a level.

After years of legal discussion going back to 2007, The Abyss was finally added to the idgames archive on September 1, 2015. While The Abyss was originally released on a BBS in the Netherlands, it was also available on the Telefragged FTP server for a short time in the directory /be/gladiator. It was later moved to a personal website. Previous versions are presumed to be lost due to link rot.