PukiWiki ('PoohKeyWeKey' without any prolonged sounds) is a wiki implementation that works on PHP 4 and 5, outputs XHTML 1.1, has many plugins (including one for bug tracking) and skins (such as one for embedded browsers), enables English and/or UTF-8 configuration, and features case-insensitive WikiNames. The formatting rules are based on YukiWiki.
PunBB is a fast and lightweight discussion board. Its primary goal is to be a faster, smaller, and less graphic alternative to otherwise excellent discussion boards like phpBB, Invision Power Board, and vBulletin. It has fewer features than many other discussion boards, but is generally faster and outputs smaller pages.
RBBS (Raving Bulletin Board System) is a bulletin board system with Web interface. Users of RBBS can post new articles and can attach responses to existing reports. Although the principal purpose of RBBS is to be used as a communication system like a BBS, it is also useful for individual use and for one-to-many communication.
The RealizationEngine is designed from the ground up to facilitate group communication and collaboration. It will store that communication to built and manage an institutional knowledge base. It is accessible from any Web browser or Web-enabled device. Classified information is easily restricted to authorized individuals. Information can be compartmentalized, restricted, or published openly, as appropriate, all from the same system. Ideas are coherently threaded, and every message is searchable in a single location and in the context of the messages related to it.