Microsoft has released a software development kit for a service that enables users who log in through one Web site to be authenticated on many others.

It's the company's latest attempt to get other Web site developers to use its Windows Live ID system, Microsoft's authentication mechanism for such services as Hotmail and Xbox Live.

The company is hoping third parties will use the kit, called Windows Live ID Web Authentication 1.0, for their Web sites or other rich-client applications.

The software kit represents a revamped incarnation of Microsoft's Passport Network authentication system, which failed to catch on much beyond Microsoft's own Web sites. Microsoft contends that its large Live ID user base, which it counts at 380 million users, already gives Web site operators an incentive to use its system.

Microsoft is offering the kit in six programming languages: ASP.NET, Java, Perl, PHP, Python, and Ruby. The application is platform independent and will work on Linux as well as XP and Vista OSes, Microsoft said.

If a Web site incorporates Microsoft's authentication, their users will be directed to a Window Live ID sign-in page hosted by Microsoft. After users log in, they're sent back to the original Web site with a special, site-specific identifier. That identifier can be used by the Web site to assign certain rights or personalized content for specific users.