Sun’s executive vice president of software, Jonathan Schwartz, told a press conference that releasing the Java source code to the open source community would lead to the creation of incompatible versions of the software, a problem known as ‘forking’.

“Java is the antithesis of forking,” Schwartz said. “It’s about compatibility.” He said compatibility between Java-based devices was of “supreme importance”.

Schwartz pointed to the example of open source operating system Linux, which has struggled to retain full compatibility between different distributions, despite such initiatives as the Linux Standards Base.

Sun is still scheduled to meet IBM for discussions on the subject in coming weeks, but the companies have not spoken about the proposal recently. Developers can already access Java source code under existing licensing rules, according to Schwartz.

At the end of February, IBM, along with advocates such as Eric Raymond of the Open Source Initiative, suggested that opening Java source code to public scrutiny would fuel its growth and widen implementation.

In a letter to Sun vice president Rob Gringell, IBM’s vice president of emerging technology Rob Smith even said his company would provide the technical resources necessary to help with the transition.

Such calls have been driven by exasperation in the development community at Sun’s Java Community Process, the Sun-controlled standards body that decides how Java is developed. Without a more dynamic process, they fear that the technology could be overtaken and eclipsed by Microsoft’s alternative .Net development environment.

But Schwartz told CNET News that the request was “kind of weird” given the ongoing problems Sun is facing after licensing Java to Microsoft. “It forked the Java community, set us back years, and is now the subject of intense antitrust litigation,” he said.