Microsoft had released Windows Live ID Web Authentication 1.0 SDK to enable a platform-neutral way of adding authentication to your application through Windows Live ID authentication service. It also makes it possible to add Windows Live controls in your application and comes with SDK containing documentation and code samples for implementation in various platforms like ASP.NET, Java, PHP, Perl, Python and Ruby programming languages etc.
Some of the published benefits:
- The ability to use Windows Live gadgets and controls to incorporate authenticated Windows Live services into your site.
- An HTTP-based, platform-neutral interface for implementing Windows Live ID authentication in your existing site, even if it is hosted by a third-party.
- Freedom from the technical details of authentication! The Windows Live ID authentication service handles this for you.
- A huge user base: any of the millions of users who have a Windows Live ID can become a user of your site.
"Web Authentication works by sending your users to the Windows Live ID sign-in page by means of a specially formatted link. The service then directs them back to your Web site along with a unique, site-specific identifier that you can use to manage personalized content, assign user rights, and perform other tasks for the authenticated user. Sign-in and account management are performed by Windows Live ID, so you don't have to worry about implementing these details."
Live ID authentication for ASP.NET applications
Dan Wahlin has a simplified implementation example to integrate Live ID authentication with your website in few minutes.
Official version of Membership Provider for ASP.NET to integrate with LIVE ID authentication has not yet been released by Microsoft, and work seem's to be underway to make it available soon.
However Peter Bromberg has experimented and has made available sample implementation to integrate it with your ASP.NET provider.
Live ID authentication for SharePoint 2007
An Authentication Provider for SharePoint 2007 has been developed by Keith Bunge, with ability to lock users and also "Authenticated Live Users" role.
This comes with it's .WSP solution that you can deploy on your farm, have your application registered with Windows Live and simply configure your Authentication Provider.
Update (Feb 10, 2008): Community Kit for SharePoint, on CodePlex, has it's release for Windows Live Authentication providers.
-- Sharad
Note: If you want to use Live ID authentication for your Windows Client, please see Windows Live ID Client 1.0 SDK