Sun Microsystems' obsession with using Java as a weapon against Microsoft is hurting its web services platform, say analysts.

Sun claimed at the JavaOne conference in San Francisco that Java was the only language suitable for the growth of web services. But analysts disagree.

Technologies such as XML, Soap and UDDI are more important for creating cross-platform communication needed to make the web services approach work, says Meta Group programme director Michael Barnes.

"It isn't about vendors creating the best platform, but how users will interact with others using different systems," said Barnes.

Vendors need to focus on the business case for web services rather than on specific underlying technologies, says Gartner vice president Daryl Plummer.

"Sun doesn't seem to realise that it's not about the platform, but the ability to reduce the time needed for business processes," he said. "It is trying to build out the infrastructure and is overlooking service provision."

By focusing on Java and its historical competition with Microsoft, Sun is hurting its own Sun One platform, says Illuminata analyst James Governor.

"Sun can't see the wood for the trees," he said. "It needs to realise there's a world beyond Java, or Sun One will be too limited to be a major success."

"Customers want to hear about interoperability and keeping their existing systems," he added.Giga Information Group told customers that "instead of touting its own separate strategy, Sun should unite vendors behind a common definition of standards" to link Java to web services.

Sun new technologies manager Andy Bush said: 'Sun One is built around XML, UDDI and Soap as much as it is around Java. All these technologies are important, none are mutually exclusive."