advent4 is a port of the original Colossal Cave text adventure to Unix. It should work without any change on HP-UX, Sun Solaris, *BSD, and GNU/Linux systems. The actual license of this program is unknown, although most people agree that it is likely to be considered to be under the public domain.
yuxtapa is a multiplayer real-time CLI game. It looks like a roguelike, but feels like a multiplayer 1st-person shooter with a focus on team play. The idea is to take the "feel" of such team based multiplayer games as Enemy Territory into an NCurses-based game with roguelike controls. Like roguelikes, yuxtapa is lightweight but surprisingly rich under the crude surface. It features several classes from which to choose, each with a different special ability, randomly generated maps which can also be saved and reloaded, and multiple game modes or objectives.