ZZT

A text-mode adventure game in the style of Rogue, ZZT already comes with a variety of game worlds. However, the real appeal of this game is the level editor with its scripting capability, which allows the creation of an unlimited number of new scenarios, stories, characters, traps, machines, and anything else players can think of.

Thanks to this open structure, ZZT has kept up a fair share of popularity for over 15 years now, with hundreds of new game worlds having been, and still being released to the public.