Microsoft has made the Sender ID framework specification for e-mail authentication available to users at no cost and with the guarantee that it will never take legal action against the users.

The Sender ID specification is now available to anybody wanting to use it under Microsoft's Open Specification Promise, which the Redmond, Wash., software maker issued on its Interoperability Web page Sept. 12, when the company promised not to take any legal action against developers or customers who use any of 35 Web Service specifications.

Microsoft has acknowledged that the move is designed to put to rest any lingering questions about its licensing terms and the ability of prospective users, particularly in the open-source community, to use the specification.

>"By putting Sender ID under the Open Specification Promise, our goal is to put those questions to rest and advance interoperable efforts for online safety worldwide," Brian Arbogast, corporate vice president of Microsoft's Windows Live Platform Development Group, said Oct. 23.