MP Bulletin Board is a text based (no SQL) forum software I worked on for a bit. It was originally created by Jcink at Jcink.com as Text File BB. Text File BB was later open sourced because Jcink lost interest in the project. MP Bulletin Board itself is also no longer under active development, but the source code was made available on Bazaar. You're free to fork it and do whatever, but it'd be appreciated if you contacted both Jcink and I before you do this.
Bazaar: bzr branch lp:~tboxley/+junk/mpbulletinboard