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 Solaris in late 1994, and was designed to run with game files from "Doom" 1.8. In the readme, the port is credited to "Dave Taylor and the rest of the folks at id Software". It runs on Solaris 2.4 and later. The distribution contained two versions: one for regular X11, and another for Sun DGA.