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Open source intranet solution with many web based applications including email, calendar, knowledge base, and instant messaging. Free online demonstration and download available.

Provides network/user management and group collaboration via Java client and web. Written in java/jsp/xml. Bootstrapped from real sysadmin work in Hamburg, Germany.

Web-based open source groupware written in Java/JSP with support for PostgreSQL, Oracle and SQL Server.

WEB-based collaboration server: Mail, Organiser and Documents manager.

A web-based Italian office communication suite for archiving digital documents. Works with Hylafax server.

JGossip is a forum implemented on J2EE platform using Struts framework. The project supports all the main features.

Lucane is a free groupware platform written in Java, designed with extensibilty in mind.

Free Open Source Portal Server allowing point and click community, content and XML syndication management on the Web, email, cellphone, other media.

Moregroupware is a Web-based Groupware written in PHP4. Includes modules like calendar, notes, todo, and contacts. It is database abstracted and uses a template engine for output.

Topic Map based java system, "a testbed for developing tools for Web collaboration", Apache license.