BSI Knowledge Manager - Central document management & knowledge base
Zimbra - Zimbra is trusted by over 500 million users to increase productivity with a complete set of collaboration tools while maintaining total control over security and privacy.
Walkaround - Walkaround is a variant of Wave, based on the Apache Wave code base, that runs on App Engine.
Kolab Community - Kolab Groupware is a secure, scalable, reliable, flexible, full-featured collaboration suite.
LSG Advocator System - Ready to meet the only legal billing software you will ever need? LSG is a global leader in the provision of Enterprise Legal IT Solutions, legal applications software and more. Request a demo today!
iRedMail - A fully fledged, free email server solution, an open source project (GPL v2).