Simple Groupware is a complete open source enterprise application offering email, calendaring, contacts, tasks, document management with WebDAV, synchronization with cell phones and Outlook over SyncML, full-text search and many more.
Open source project that offer summary and download services on this page is a project that carry out their development work on other open source development sites. Their work is linked to this page via a feature called OFI, and their work is not carried out here on OSDN site.