Microsoft is having another attempt at a service that enables users who log in through one website to be authenticated on many others.

It has launched a software development kit in the company's latest stab at getting other developers to use its Windows Live ID system, Microsoft's authentication mechanism for services such as Hotmail and Xbox Live.

The software kit represents a revamped incarnation of Microsoft's Passport Network authentication system, which failed to catch on much beyond Microsoft's own sites. Microsoft contends that its large Live ID user base, which it counts at 380 million users, already gives website 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 website 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 site with a special, site-specific identifier. That identifier can be used by the website to assign certain rights or personalised content for specific users.