Two interesting projects I recently came across:
Description from the author:
KeeperRL is a Dungeon Keeper and Dwarf Fortress inspired dungeon simulator built on top of roguelike mechanics. My vision is that you are a Sauron-like character, searching for ultimate knowledge of destruction. What makes the game different from other RTS is that you can, and are encouraged to, control your main character and lead your minions to an open war. The characters use equipment, scrolls, potions, spells, and other things you would expect in a roguelike. Combat is turn-based and very tactical. The whole world is procedurally generated, and there is adventure mode too.See a video of the (still in ASCII graphics) action here and the GPL licensed code here. Latest development release can be downloaded here (Win&Linux).
A real classic is being reimplemented as OpenIG (follow the development blog here). Interestingly the original developers have granted the rights to all the game's data to be freely (as in beer I assume) distributed with the new Java based engine.
Time to jump into the 4X games again ;)