Zimbra
From WikiCover
Zimbra is the leading provider of open source messaging and collaboration software for businesses, service providers, educational institutions, and government agencies. The Zimbra Collaboration Suite features an AJAX Administrative user interface and a browser based client to dramatically improve the messaging and collaboration experience for administrators and end users alike. Zimbra supports Windows, Apple, and Linux desktops and works with Microsoft Outlook as well as today's most essential PC and mobile devices including the Blackberry, Treo and Motorola Q. Additionally, Zimbra supports popular server operating systems such as Red Hat, Mac, Ubuntu, SUSE, Fedora and more. The Zimbra Collaboration Suite was voted Best Enterprise Project in the inaugural 2006 SourceForge.net Community Choice Awards, received a SIIA Codie award for Best Communication or Collaboration Solution, named a winner in eWEEK's Seventh Annual Excellence Awards program, in the Enterprise Collaboration category and won InfoWorld's 2007 Application Innovator Technology of the Year Award.
Website: http://www.zimbra.com/