Open-Xchange

The Open-Xchange Collaboration and Integration Server Environment allows you to store appointments, contacts, tasks, emails, bookmarks, documents and many more elements and share them with other users. This environment can be accessed via any modern web browser and multiple fat clients like KDE Kontact, Ximian Evolution (announced), Konqueror, Mozilla Calendar and many more. Every 3rd party product can access this application over many different interfaces like the WebDAV interface (XML), LDAP, iCal and HTTP(S).