Sun executives said at the JavaOne conference that the company would release Java to open source. But they did not provide a timetable or any details about how they would structure the licensing. Sun has been criticized in its past efforts around OpenSolaris and OpenOffice for not using the traditional GPL licenses used by most open-source software.

Ari Kaplan, president of the Independent Oracle Users Group, said that users will have to wait and see what exactly Sun will be releasing to open source before knowing the full significance of the announcement.

"There wasn't that much detail to the announcement,"Kaplan said. "Going from a proprietary system to open source, people still have to wait and see what will be open source -- all of J2EE, the application server, the development tools or a more narrow part."

In addition, he said, users always have concerns about how customer service will be affected when a proprietary tool gets released to open source.

"The other concern people have ... is how the quality of support calls and service calls get affected,"he said. "The mainstream is generally positive as long as the quality, scalability, security and compatibility remain intact. Those things still remain to be seen."