Calendar -- Shared calendars
BugTracking -- Issue tracking
General -- Complete groupware solutions
Servers -- MS-Exchange-style groupware servers for desktop clients
CMS -- Content management for websites
Personal -- Personal organisers
CRM -- Customer relationship management
Local -- My notes on groupware systems
ProjectBased -- Project-based organisation software
GrantBow - the definitive review section
Another list of groupware products, including the proprietry ones
