Microsoft has vowed to drop intellectual-property and patent claims to 35 Web service protocols it has developed, making them available licence-free for anyone to use.

The hope is that the move will open up its identity infrastructure, and the protocols include the current versions of protocols in the WS-x security stack, plus those that are used as the foundation for the company's year-old Identity Metasystem infrastructure and its InfoCard and companion CardSpace technology.

The announcement was posted on the blog of Microsoft's identity architect, Kim Cameron, and included endorsements from third-party rivals, including Red Hat.

Cameron and colleague Mike Jones worked to get OPS approved in the executive and legal ranks at Microsoft. Bob Muglia, senior vice president of Microsoft's server and tools business and Microsoft's patent lawyers signed off on the OPS document on Tuesday.

Cameron wrote: "The goal was to find the simplest, clearest way of assuring that the broadest possible audience of developers could implement specifications without worrying about intellectual-property issues - in other words a simplified method of sharing 'technical assets.' "

OPS is a legal document that hinges on a "promise not to assert" i.e. enforce patents. It is "self-executing", meaning developers don't have to sign anything to use the protocols. Similar legal documents not to assert rights over patents have been used recently by IBM, Sun and Oracle, and is similar to another promise not to assert patents that Microsoft made last year regarding its Office 2003 XML Reference Schema.

"This is a significant step forward," says Jamie Lewis, Burton Group president and CEO. "Microsoft has been talking consistently about wanting to see not only inter-operability but functional equivalency for its identity technology on other platforms."

While licensing was the major hurdle, lesser details also have to be worked out, including the meta models and schema that Microsoft used to implement its own identity technology, such as InfoCard and CardSpace. Microsoft has not reached decisions about how that will be accomplished.