Here are some files, tools and tutorials which were crucial in developing KeeperFX.
I wouldn't be able to "synchronize" my source code with the original binary data without a good disassembler. After some research, I've chosen IDA Pro - it's a great tool, and with additional plugin it can even generate pseudo-C code for some functions.
Here's the IDA Pro project which I made from Dungeon Keeper executables:
Download IDA Pro project for KEEPER95.EXE from DK Gold
Download IDA Pro project for KEEPER.EXE from DK RC1 (pre-release version)
Here's a collection of mentor scripts. Based on these, you may create or record a script for your language.
Download KeeperFX Mentor Scripts v1
And here is my tutorial for EXE-to-DLL file hacking
How to change EXE into DLL tutorial
Download PE/DLL Rebuilder of Export Section (PeRESec) w32+source
To be able to understand the Bullfrog Engine structure, I searched for executables from Bullfrog's games which would contain Debug Information block. Debug Info usually contains names of functions, which is extremely helpful in determining how the code works.
Here is a pack of all executables with Debug Info I could find. There are also scripts that allow to extract these debug information, which allows to load it into a debugger.
Download Bullfrog Debug Executables Pack
Please report any problems or dead links.
Read README file before using any of the programs!