Ancient Domains of Mystery (ADOM) stands out among the roguelike games. It is the work of a single person, Thomas Biskup, and though it is free will never be open source. But unlike the other closed-source games, it is constantly being developed. Thomas Biskup started working on it in 1994; in 1997, it was voted the best freely downloadable game, easily beating Doom!
If you enjoy Roguelike games, you'll want to try this one. It features primitive ANSI graphics (like most Roguelikes) but it is very indepth, even more so than Nethack. The game takes place not only in dungeons, but on the overworld and in towns as well.DOSGames
Download and try out one of the most detailed computer RPGs ever created (with hundreds of levels, randomly generated anew for each game, 200 combinations of races and classes, more than 600 items, 400 monsters, dozens of quests, skills and a lot more!).
Astounding, immense, this is ADOM (Ancient Domains of Mystery). I should have written a review for this game ages ago, but it didn't convince me at all, so it laid as dead on my HD, until I decided to give it a chance Shame on me! this is one of the most detailed game i have ever seen, it is HUGE.
If there is one game that professional developers and publishers hate, it's Ancient Domains of Mystery (ADOM). The final version (1.0) released in late 2002, this freeware role-playing game that fits on a single floppy offers an unprecedented depth of character development and a length of gameplay that easily matches the longest games ever released. In fact, ADOM offers more replay value than any game released in the 21st Century, and unlike many of those games, it remains fun no matter how often you replay it.