Twenty-five companies, including Sun Microsystems Inc., BEA Systems Inc., XenSource Inc., and Novell Inc., have agreed to join the , which was announced officially at Microsoft's IT Forum in Barcelona, Spain.

The Alliance will focus on promoting interoperability with Microsoft software in areas such as systems management, virtualization, identity management, data access, connecting multiple portals through Web services-based single sign-ons (SSOs) and developer tools, according to Jason Matusow, senior director for interoperability at Microsoft.

'We want to create a forum that creates an environment for getting things done,' Matusow said. Vendors that join the group can still decline to make their products work with another member's if they believe it is in their business interest.