i just want to play single player :]

Having had my brief stints as Heroimms, I can pretty confidently say you're not going to get ahold of any of CF's actual code. Even to see the information regarding area building requires signing a non-disclosure agreement. If you consider the amount of hours our various Implementors, Builders, etc, have put into the MUD, you can understand why they wouldn't want to risk people running off with copycats.

However, that said, the stock ROM code which CF derives from CAN be downloaded, and you can make your own little mini-mud to play around in. I've done it once years ago, but don't remember how it was done. It's kinda fun being God for awhile, but a Multi-User Dungeon (MUD) without the Multi is pretty boring quick.