Message Boards

eForum
Web discussion forum. (Java)
http://www.jcorporate.com/html/products/eforum/eforum_descrip.html

PBLang
A customizable message board with many professional features, and it does not require a database. (PHP)
http://sourceforge.net/projects/pblang/

Phorum
Web based discussion software. (PHP)
http://phorum.org/

SMF - Simple Machines Forum
A professional grade software package that allows you to set up your own online community. Support, themes, and mods are all provided through the site. (PHP, MySQL)
http://www.simplemachines.org/

Vanilla
An open-source, standards-compliant, multi-lingual, discussion forum for the web. (PHP, MySQL)
http://getvanilla.com/

VAXbb Project
A fast, text-based bulletin board system for the Web. (Perl)
http://www.omar.org/opensource/vaxbb/