Zimbra has released a beta of its enterprise collaboration software - an open-source alternative Lotus Notes and Exchange Server.

The start-up that lured Scott Dietzen away from his former job as chief technology officer of BEA has called the software the Zimbra Collaboration Suite. It includes e-mail, contact and calendar software.

It includes an AJAX (Asynchronous JavaScript and Extensible Markup Language) client, as well as server software. In addition to Zimbra's own code, the suite employs a number of open source products, including the MySQL database and the Apache Software Foundation's Lucerne indexing software.

AJAX is a group of Internet technologies designed to give Web browsing a smoother, more dynamic feel. By using them in its collaboration product, Zimbra hopes to develop full-featured, easy-to-use messaging software that can be accessed using any Web browser, said Stephen O'Grady, a senior analyst with RedMonk.

The most widely used enterprise messaging products have not always worked well with Web browser clients, because they were designed for client-server rather than Web-based networks, O'Grady said. "This is a space that's really crying out for innovation," he said.

Google's Gmail service has used AJAX technologies to incorporate advanced features such as spell checking and search without becoming slow and clunky, and Zimbra is now trying to apply some of those same techniques to its own software, O'Grady said.

In the coming weeks, Zimbra plans to launch a service called the Zimbra Network, which will include product support and other services, according to Wednesday's announcement. Pricing for the Zimbra Network was not announced.

Zimbra is not the first company to take a shot at open-source collaboration products. In February, Novell released code from its NetMail server as part of its Hula collaboration server effort, and other organisations, such as Scalix and Lotus founder Mitch Kapor's Open Source Application Foundation, also are involved in the space.

The Zimbra Collaboration Server runs on two versions of Linux: Fedora Core 3 and Red Hat Enterprise Linux 4. The Zimbra client, which can be accessed using the Firefox or Internet Explorer, runs on Windows, Mac OS, and Linux, the announcement said. Users can also access the Collaboration Server with existing mail clients such as Outlook or Apple Mail.