The software, called Simple Object Access Protocol (SOAP), lets businesses connect their computing systems over the Net so they can conduct online transactions with customers and partners. SOAP is based on the XML (Extensible Markup Language) Web standard.
SOAP, which was created by Microsoft but does not require any Microsoft software, is a network protocol that lets software objects developed using different languages communicate with each other.
Sun is the second company to flip-flop on SOAP. In April, IBM also reversed its stance, saying the need for the software industry to find a way for businesses to link their different computing systems outweighed competitive issues.
Sun, IBM and other Java proponents initially balked at supporting SOAP. Sun executives had earlier this year said SOAP was "pure hype with no value."
The original version of SOAP too closely favored Microsoft technologies over industry standards, said Anne Thomas Manes, Sun's director of business strategy. But thanks to the influence of IBM, the new version of SOAP includes less Microsoft-specific technology and more support for Web standards, she said.
For instance, the original version of SOAP used a proprietary Microsoft technology linked to the company's BizTalk Server software. Now, the new version supports the World Wide Web Consortium's XML Schema Web standard. Schemas tell a computer reading an XML document how to interpret special coding.
Manes said Sun decided to support SOAP after inspecting the new version of the technology that was released in April.
"We think SOAP is a good starting point for XML messaging," said Anne Thomas Manes, Sun's director of business strategy, during the JavaOne conference. "You need a standard messaging system because it makes life easier."
SOAP is intended to solve a dilemma faced by businesses over competing programming models. For the most part, software developers have settled on two ways to write business software. Microsoft supports a model that steers businesses to use its dominant Windows operating system. Sun, Oracle, IBM and dozens of others support a model based on the Java programming language.
SOAP would serve as a common communications format that would link the different programming models, allowing businesses with different computing systems to connect and conduct trades online, regardless of the model they use.
With Sun on board, SOAP supporters believe the technology has a good chance to become a Net standard. Microsoft, IBM and nine other firms in May submitted SOAP to the World Wide Web Consortium (W3C) Internet standards group.
Bob Sutor, IBM's program director of XML technologies, said Sun's support of SOAP will make the standards effort easier because there won't be any disagreements in the process.
"This is not a Sun thing or Microsoft thing. It's seen as a good technology," Sutor said. "We have to just connect everything together. In real life, people use different hardware, different operating systems, different (programming models)."
Manes said Sun will suggest that the standards group use SOAP as the starting point in developing an XML messaging standard. The W3C is considering SOAP and 11 similar communications protocols before determining the requirements for XML protocol standards.
Manes also said the SOAP technology could be used as part of a larger XML standards effort by the United Nations and a non-profit consortium of technology companies called Oasis.
Oasis, which includes IBM, Sun, Oracle and the United Nations, is working to create a uniform model for XML usage. Sutor, who also serves as Oasis' chief strategy officer, said SOAP is being considered but no decisions have been made.