San Mateo, Calif.-based Scalix Corp. on Monday announced Version 11 of its eponymous collaboration software. And Zimbra Inc., also based in San Mateo, released Version 4 of its Zimbra Collaboration Suite (ZCS) with a new tool allowing users to embed fully functional and editable documents and spreadsheets in e-mails.

There have long been alternatives to the triumvirate -- Exchange, IBM's Lotus Notes and Novell Inc.'s GroupWise -- that has dominated the messaging and collaboration market. They include software from Mirapoint Inc., Rockliffe Inc., IPSwitch Inc., U.K.-based Gordano Ltd. and others, according to Michael Osterman, an analyst at Black Diamond, Wash.-based Osterman Research Inc.

But most upstarts, including both proprietary and open-source solutions, have Microsoft in their sights. Microsoft plans to release Exchange 2007 early next year, but only for 64-bit versions of the Windows operating system.

"There are a lot of companies running Exchange 5.5 or Exchange 2000 that are looking to upgrade but don't necessarily need integration with Microsoft SharePoint or Live Communication Server, or want to lower their costs," Osterman said.

One way is to move to a solution such as Scalix, which not only has a community edition that users can try for free, but also lets companies move their employees to a Web browser-based e-mail interface that leverages AJAX to provide desktop-app-like features.