The gameplay of this remake is supposed to be same as in first version of Dungeon Keeper. Only graphics is better, and one of the main goals is easy modding (add your own creatures and other objects, editing properties of game elemements). The engine loads every level prepared for DK1 or Deeper Dungeons.
The main problem with this remake is lack of any AI algorithms. Development of those may take quite lot of time, as its author, IKSLM, works on the code alone.
Interactive demos are already available for download. They show impressive graphics of the engine used in this project. But the game mechanics is still unfinished, so those demos are still not playable.
As the author claims, final version of NBKe will be an open-source program.
Dungeon Digger is a 3D RTS game based on Dungeon Keeper. It is completely open-source. As for now, it doesn't look impressive, but that's because their authors want to implement all the AI systems and game mechanisms, and only then take care of its look and graphics.
As a programmer, I must say this project is very impressive. Its authors seem to have very professional approach to the project, and its development goes smoothly.
OpenDungeonKeeper is an clone of Bullfrog's Dungeon Keeper 2. It will support nearly all the features of Dungeon Keeper 2.
In this project, there is no version released yet. But its development seem to continue. Programmers are probably from Germany, as they've created project's forum in german language.
Please report any problems or dead links.
Read README file before using any of the programs!