Microsoft this week plans to unveil at the Professional Developers Conference a new workflow subsystem for its client and server operating systems that will become a foundation service available on the Windows platform.

The company will take the wraps off Windows Workflow Foundation, which will pull together a number of current workflow technologies spread throughout Windows products, including Windows Workflow Services (WWS, formerly called Windows Orchestration Engine).

The single technology will provide a common service for building workflow to support business- process automation in places such as Office-based collaborative applications, composite Web-services applications, Microsoft's business applications and the provisioning capabilities of Microsoft's identity management platform.

Critics, however, wonder what other products will be required to run Workflow Foundation and how open it will be, especially given that numerous vendors provide proprietary workflow engines for their Windows applications.

Also at the conference, Microsoft plans to introduce a number of corporate servers for its Office System, mostly designed around Version 3.0 of Windows SharePoint Services, which includes content management and online workspace tools. The company also plans to offer a range of new tools, including Atlas, for developing sophisticated Web-based applications using Asynchronous JavaScript and XML.

A major topic will be Vista, the client operating system first demonstrated at the Professional Developers Conference 2003, when it was called Longhorn and before some of its core features were removed.

"They need to tell everybody what Windows Vista is," says Joe Wilcox, an analyst with Jupiter Research. "We know what it isn't because of all the things that were removed."

Added is Workflow Foundation, an operating system subsystem that joins Windows Presentation Foundation (formerly Avalon), which supports rich interfaces. Included is Windows Communications Foundation (formerly Indigo), middleware to support service-oriented applications. Both subsystems have been back-ported to XP and Server 2003, but it is not clear if Workflow Foundation will join them.

Microsoft briefly mentioned Workflow Foundation last week at its Business Summit, where it laid out the future of its business applications that were rebranded Microsoft Dynamics.