Groupware

Groupware applications are a little bit like a web-based version of Outlook -- shared calendaring, contact lists, tasks/to-do's, etc. They can also serve as a kind of enterprise portal, with news and articles.

Often includes elements of Community CMS systems, and also Project Management and Document Management.

There are also a variety of online/ASP-type groupware systems, such as Intranets.com, that are worth looking at. Intranets.com in particular is interesting because it offers a synchronization tool that works with Palm devices and Outlook, for everything from To Dos to Contacts and Calendaring.

Of the ones below...I don't really like any of them :( Suffers from some of the same problems as PostNuke -- too many developers, too much bad code, and too many ideas about which direction these projects should go.

For some strange reason, many of these projects are based out of Germany. Why? Maybe the Germans are anal about organization?!

Mimerdesk
Purports to be a "virtual desk" that will also be targetted at eLearning applications, to manage things like courses and course material.

Moregroupware
Based out of Germany. Have come a long way, and is one of the packages that "sucks less".

PHP Groupware

PHP Projekt
Supports LDAP

TUTOS
Stands for "The Ultimate Team Organization Software"

TWIG
This software is part of Mitel's for-pay options with e-smith

Sherpath
Very extensive groupware system. Also generates RPMS for the Mitel e-smith server.