The Zarafa Collaboration Platform is a Microsoft Exchange replacement. The Open Source Collaboration provides an integration with your existing Linux mail server, native mobile phone support by ActiveSync compatibility and a webaccess with "Look & Feel" similar to Outlook using Ajax. Including an IMAP and a POP3 gateway as well as an iCal/CalDAV gateway, the Zarafa Open Source Collaboration can combine the usability with the stability and the flexibility of a Linux server. The proven Zarafa groupware solution is using MAPI objects, provides a MAPI client library as well as programming interfaces for C++, PHP and Python. The other Zarafa related packages need to be installed to gain all features and benefits of the Zarafa Collaboration Platform .