wolf4sdl (Wolfenstein 3D engine) Wolf4SDL is an open-source SDL port of id Software's classic first-person shooter Wolfenstein 3D. It is meant to keep the original feel while taking advantage of some modern improvements. This build includes the game data files from the shareware/demo versions of Wolfenstein 3D and its sequel Spear of Destiny. To play the full versions of the games, you need the *.wl*, *.sod, and/or *.sd* files from your installed copies of the games. Copy them to "/usr/share/games/wolf3d". Filenames must be all-lowercase.