The full name is:
Slaves to Armok: God of Blood
Chapter II: Dwarf Fortress
Incredibly fun and diverse rogue-like with random levels. Can you live 100 years? Can you live 1 year without a horse catching fire? Will your dwarves keep out goblin invaders? Can you build a huge waterproof walled fortress around a human city, then dig into the aquifer, thereby killing all inhabitants of the nasty human city? Can your city survive off of living on cat and dog meat? You can find out!
Saves settings to: Application dir
Download Size: 5.5 MB (3.3 MB without sound)
Size in use: ~100 MB (it creates its own worlds)
Modifies one key HKLM\SOFTWARE\Microsoft\DirectDraw\MostRecentApplication\Name: "dwarfort.exe"
Dependencies: DirectX (DirectDraw specifically, see Regshot info)
Notes: Fairly CPU intensive, despite the fact that it's text based. Oh, that reminds me. You can also get graphical tilesets for the game.
Website (and download link): http://www.bay12games.com/dwarves/
Edit: added link