The Bubble User Bulletin Board System, or just "Bubble" for short, is my attempt at making a single-threaded bulletin board system modeled after the one I used in college (the UBB, at Boston University 1992-1996 or so). It's still in a very primitive state, but already usable. No documentation yet, except for the README, but its functioning should be pretty obvious. It's designed for Unix systems and requires Perl. Download it and give it a try; whether you find it useful or not, I'd like to hear from you.