Microsoft has made available prerelease versions of the Windows Communication Foundation and Windows Workflow Foundation, which comprise two of the core building blocks within Windows Vista. The company has also issued a Go-Live license for each, signifying the products' state of readiness.

The idea of the releases is to enable developers to build applications and solutions on the new technology and be ready by the time Vista reaches store shelves. The two foundations are part of the new WinFX programming model, which Microsoft has backported to Windows XP and Windows Server 2003.

The Windows Communication Foundation, formerly known as Indigo, will serve as the next-generation communications platform in Vista and help developers build applications without worrying about networking complexities by simply calling Indigo functions.

Windows Workflow Foundation was introduced at PDC 2005 in September and consists of a group of APIs, the engine to make it run, and Visual Studio tools that enable developers to take advantage of business workflow within their applications. Previously, creating a workflow engine was an expensive and time-consuming undertaking.

Both technologies are labeled Beta 2, indicating the second major milestone for Windows Vista is fast approaching. Microsoft is expected to issue Beta 2 of its new operating system in February and make the test release more widely available than previous betas.

"Customers have told us that they want to use these technologies in live operating environments even if they are unsupported," the company said. "This is a choice that we want to allow customers to make and the Beta 2 milestone is a significant software quality level."

The downloads are available now from MSDN and run on x86, x64 and Itanium based machines. The Go-Live license, which allows the software to be installed on production systems, requires a Passport account for registration.