Doom (1993 video game)
The ability for others to create custom levels and otherwise modify the game using WAD files turned out to be a popular aspect of "Doom". Gaining the first large mod-making community, "Doom" affected the culture surrounding first-person shooters, and also the industry. Several future professional game designers started their careers making "Doom" WADs as a hobby, among them Tim Willits, who later became the lead designer at id Software.
Official versions of Doom
"Doom" was ported to IRIX during the summer of 1994 by Dave D. Taylor. It was designed to run on IRIX 5.2 and later. IRIX "Doom" was originally based on the unreleased MS-DOS version 1.5, though later updates were based on versions 1.6 and 1.8. No effort was made to take advantage of SGI's advanced graphics hardware, and like many other ports the game was rendered entirely in software.