Ancient Domains Of Mystery (ADOM) is now available for Windows, OS X, and Linux, offering this Roguelike that's starting to live up to its title, since it was first released in 1994. There's a post on the game's blog covering the news, including details on a new patch that accompanies the release. Here's the description of the game:

ADOM (Ancient Domains Of Mystery) is one of the most successful roguelike games ever created, boasting a brilliant mix of story, RPG, exploration, and intensely strategic and flexible combat. The Steam version adds various Deluxe features like achievements, difficulty level customization and various play modes (e.g. a story mode allowing to save and restore games, a weekly challenge game, an exploration mode and more). ADOM has been in development since 1994. In 2012 its development was revitalized with an immensely successful crowdfunding campaign on Indiegogo, now allowing us to offer ADOM both with ASCII and graphical modes enabling you to choose freely.