Developers can use the implementations to integrate .Net with Java, Sun said.

By offering them via open source, they can more easily be used in products, Badani said.

Sun will make the implementations available via Sun's Glassfish project, which is an open source development effort for Sun's Java System Application Server. Preliminary code for the specifications is expected in three to six months, followed by another prerelease of code in the Java Web Services Developer Pack.

Microsoft endorsed Sun's effort in a prepared statement.

"Microsoft is pleased that Sun shares our goal of using the WS-* specifications to provide interoperability between applications regardless of the underlying platform. Technical collaboration on WCF and WS-* specifications is a natural part of our ongoing efforts with Sun and important to our mutual customers," Microsoft said.