Sun executives confirmed the long-anticipated open-source move during the JavaOne conference here last week, although they said they still need to devise a detailed plan to ensure that Java isn't put on diverging paths.

Java consistency is essential to David Holberton, a J2EE developer at a large aerospace company he asked not be named. Currently, the versions of the Java Virtual Machine the company's J2EE applications run on are consistent, Holberton said.

An open-source Java implementation "opens up innovation, but I'm concerned about fragmentation," he said. Nonetheless, Holberton added that he's "fairly confident" Sun can avoid any splitting of the code, citing the company's longtime efforts to ensure a consistent development environment.

Several other users, including Haroon Rafique, a systems developer at the University of Toronto, also expressed concern that Java could head down different paths once developers get access to the source code under whatever open-source plan Sun devises.

"My concerns would be if they do open-source it -- and don't keep control over it -- then you are going to have competing implementations," said Rafique.