- Main article: Unix
Early Unix systems provided only a text console. Games such as Adventure would describe your location and accept commands (like "north", "take lamp", "wear amulet", "fight", or "inventory"). You would sometimes need to guess the commands. These games also appeared on other platforms. These games are also found on other platforms, and continue to exist today as "interactive fiction".
When video screens became available, it became possible to position characters on the screen. The "graphical" game rogue, bundled with the BSD variant of Unix, drew itself on the screen as ASCII art. Other persons made rogue clones and several other roguelike games.
Eventually, the X Window System, Version 11 (X11) brought windows and graphical user interfaces to Unix. (Mac OS X uses its own graphics instead of X11.) This allowed arcade-style games with actual graphics. The free XFree86 implementation of X11 became dominant, but recently XOrg has displaced it.
The rival GNOME and KDE desktop environments for X11 included several games in the style of Solitaire, Minesweeper, and Tetris. The Simple DirectMedia Layer (SDL) library helped spread full-screen games such as Battle for Wesnoth.
Actual Unix hardware varies greatly, from non-X11 machines up to high-end systems with ATI or nVidia cards and Linux drivers. Unfortunately, apart from Mac OS X and Linux/x86, where proprietary ATI or nVidia drivers are available, 3D graphics performance in Unix is poor even on machines with new ATI and nVidia cards. This limits the play of OpenGL games.