Joomla - building on code from widely used Mambo cms makes full use of web interface for admin.
PhpNuke - has been used by several sites attempting to jump start the process.
PostNuke - a fork of phpnuke, with more co-operative development. Seems to be flourishing, and has many architectural advantages over phpnuke. See it in use at Mad Hatter's IMC
Xaraya - web application framework useful for creating community web sites and other functionality useful to IMCs
PhpSlash - What phpNuke forked from. However it's now template driven and using phplib's session management.
Zope is an application server as opposed to page server, it is slower than page server but they can be combined. Has more robust security model and easier to build web applications with.
Envolution A non-GPL fork of PostNuke v0.714 ( not free as in freedom software )
Typo 3 Complete CMS, very extendible and customizable, runs in shared hosting environment, PHP codebase, configuration is time-consuming for people not used to its scripting language
zope - which powers this wiki web, and is really neat.
and replaced as untrue as this Twiki is powered by cgi scripts.
Zope has zwiki as it wiki.
-- PietroFerrari - 11 Jun 2002
added more links and removed defunct link to bandwidth coop material that has now moved to this site.
-- SpaceBunny - 27 Apr 2003
started
-- AlsteR - 08 Aug 2004
Changed URLs to Shorthand. Added Typo3, OpenCMS, TikiWiki and some annotations