HSPNotes
This script uses HTML embeded Perl code to serve threaded discussions. Perl embedding is done by a small CGI Script. This discussion board is very lightweight and has a very clean output. It intentionally has none of the fancy features of some of the big bulletin boards. It concentrates on serving information. Threads can be generated on the fly or you can have them saved as HTML files for best performance so that search engines can index them. You can run multiple forums with one script or install multiple scripts using the same embeded perl engine. HSPNotes is totally free and the embedded perl engine can be reused for anyother HTML embeded perl scripts.