The test software was made available to members of the Microsoft Developers Network and the company launched a new MSDN blog to keep its community updated.

Our Beta 1 release is a preview of WinFS, Microsoft’s platform that allows developers and users to unify, organize, and explore data in ways they couldn’t before, wrote program manager Vijay Bangaru. This release contains the core of the capabilities we’ll have at R [release to manufacturing].

WinFS was originally supposed to be a core component of Longhorn, the next version of Windows, now known as Vista. But Microsoft removed the technology from the Vista roadmap after feedback, in order to hit a 2006 delivery date for the OS.

The current plan is to ship WinFS separately, either as a download or an OEM pre-install on Vista. Microsoft has not yet revealed whether WinFS will be available for Windows XP, but the beta software released yesterday will be usable on XP.

We’re still working on exactly which platforms to support for R – there are a set of difficult tradeoffs in terms of features that WinFS can support on each platform, wrote program manager Quentin Clark.

There will also likely be commercial considerations – if Vista adoption is slow, WinFS and the applications built upon it could become a nice carrot for users still on XP or earlier versions of Windows to upgrade.

Likewise, in the less likely scenario, if Windows Vista adoption is extremely fast, there may be less incentive for Microsoft to back-port the WinFS software to a dwindling XP user base.

But that’s all speculation right now. No R date has yet been set for WinFS, but the developer team blogged that it will be still be in beta testing when Vista ships next year.

WinFS is designed as a relational file management overlay to NTFS, the basic file system used by the latest versions of Windows. The idea is to allow concepts like items and relationships to be defined, to applications can work with each others’ data.

Clark gave the example of two data items, a document and a contact, being logically linked through an author association. Applications built on WinFS would be able to recognize and work with that relationship.

Bangaru wrote that the initial beta software includes the definitions of these concepts, as well as object APIs that will enable developers start to write code supporting them. It also includes the beginning of Windows Explorer support for WinFS.

The developer team wrote that they expect multiple beta versions and community technology previews to be released before the software is finally released. Microsoft has set up a newsgroup for MSDN members to discuss the new software.