Zimbra has worked hard on the marketing of its core Zimbra Collaboration Suite (ZCS) as an open source Exchange alternative. It’s also worked hard on the technology, the end result being a good customer base, mainly in education plus the small to medium enterprise sector. It has also attracted a lot of media attention and at the end of 2007, was acquired by Yahoo!
The company continues to operate as an independent entity and a fully open source edition of ZCS is available for free download. However, for full support of MAPI plus access to the Zimbra Connector for Outlook (ZCO), it’s necessary to subscribe to one of the commercially licensed network editions. A hosted version of ZCS is another option, primarily aimed at education users.
Java is used for the server side components, with the host Linux file system used for the message store (one file per message). An embedded MySQL database manages mailbox metadata, and use is made of a variety of other open source components including Apache Tomcat and the Postfix MTA. ZCS can be hosted on Red Hat and SUSE Linux Enterprise platforms together with Debian, Fedora Core and Mandriva distros. Ubuntu is another very popular platform with Mac OS X also supported, although some features aren’t available on Apple hosts.
AJAX technology underlines a neat graphical management interface in ZCS with the ability to integrate other applications, through the use of so-called Zimlets, another key selling point.
On the client front Zimbra is keen to promote its AJAX based browser interface which gives access to all the groupware features but, equally, boasts its ability to support virtually any client environment. Support for MAPI is delivered via the Zimbra Connector , handling both messaging and collaboration and using the same secure web services protocol as the Zimbra AJAX client. The Zimbra Connector also supports cached mode for disconnected operation and through support of SSL allows remote users to connect to the server without the need for a VPN.
Like the OXtender, ZCO can only be used with Outlook 2003/2007, but more than matches what the other vendors can do in terms of functionality. Indeed it provides virtually a full Exchange experience, with a single folder hierarchy, public folders and address books, shared calendars and the ability to check free/busy time when scheduling events.
MAPI support is also being extended server side, to enable ZCS to interoperate with Exchange servers. This option is still in the early days of development, the only tangible so far being beta support for sharing calendar information with Exchange Server 2003.
Not so intangible are migration tools to help move to Zimbra from other platforms, particularly Outlook and Exchange. Plus support for over-the-air synchronisation of mobile devices, making for a very complete messaging and collaboration package that compares well to what Exchange is able to deliver.