Microsoft is making development progress with its next-generation Windows programming technologies, and is encouraging developers to kick the tires on some of its core components months before they are set to ship.

On Wednesday, Microsoft made available for public download on the Microsoft Developer Network (MSDN) site the January Community Technology Preview (CTP) build of its WinFX programming technologies. Included in the January WinFX CTP are refreshed releases of the Windows Communication Foundation, or WCF (formerly code named "Indigo"); Windows Presentation Foundation, or WPF ("Avalon"); and Windows Workflow Foundation (WF).

Microsoft describes WinFX as the next-generation Windows programming model. As such, WinFX includes a set of application programming interfaces (APIs) and exposes a set of class libraries and run-time components for developing and running applications. WinFX will be part of Vista and will also work with Windows XP and Windows Server 2003.

The new WinFX CTP includes enhancements to WCF, WPF and WF. The WCF updates include new service configuration editor and service trace viewer functionality, as well as support for REST-based services. The January WinFX build of WF includes new policy-activity functionality, rules designer advances and support for XAML (eXtensible Application Markup Language) as the workflow file format. And the January build of WPF adds support for Microsoft's forthcoming Microsoft Express suite of design tools; support for frame-based animations; and support for in-browser applications, according to Microsoft.

"They are really pushing the use of XAML for business process, which is very unique and compelling," said Ron Schmelzer, a senior analyst with ZapThink LLC. "They're already getting WCF and WF in the mainstream."

The January WinFX CTP will run on Windows XP and Windows Server 2003 but not on any beta or CTP builds of Windows Vista or Longhorn Server. Microsoft's plan remains for WCF, WPF and WF to be integrated into Vista, however, company officials reconfirmed.

The final version of WinFX is slated to ship simultaneously with Windows Vista, in the latter half of 2006.

CTP product builds are not considered to be beta quality. Instead, they are interim snapshots, intended to provide testers with a glimpse of where particular products are, in between full-fledged beta releases.

Microsoft has been releasing monthly CTPs of WinFX since last Fall. The last full-fledged beta of WinFX was in July 2005.

Microsoft also announced Wednesday that it is making souped-up beta builds of WCF and WF available to testers who want to license them under what Microsoft calls a "Go Live" license. A Go Live license allows developers to deploy applications based on given technologies in production environments. Microsoft's developer division has made a number of technologies available under the Go Live license.

Ari Bixhorn, Microsoft's director of Web services strategy, characterized the WCF and WF builds that Microsoft is making publicly available for download under the Go Live license as "beta-plus-plus quality." He said the builds have undergone all the regular beta reliability tests, plus some additional stress testing. Bixhorn said Microsoft is making these two WinFX components, but not WPF, available under the Go Live license because they lend themselves to scalability testing "across thousands of users."