Doom (1993 video game)
Doom (typeset as DOOM in official documents and stylized as DooM in other media) is a 1993 first-person shooter (FPS) video game by id Software. It is considered one of the most significant and influential titles in video game history, for having helped to pioneer the now-ubiquitous first-person shooter. The original game was divided into three nine-level episodes and was distributed via shareware and mail order. The Ultimate Doom, an updated release of the original game featuring a fourth episode, was released in 1995 and sold at retail.
Strife (1996 video game)
After the game's official support ended, game engine recreations of "Strife" were created by Doom source port developers through reverse engineering. Notably authors were Jānis Legzdiņš (author of the Doom source port Vavoom), Randy Heit (author of ZDoom), Samuel Villarreal (author of "SvStrife"), and James Haley (author with Samuel Villareal of Chocolate Strife). Except for the last, these allow for high resolution graphics modes, better mouselook, and expanded modding capabilities.