After months of hinting, Sun has confirmed it will release its Solaris operating system under an open source licence. When though is a different matter.

Sun spokesman Russ Castronovo confirmed that an open source Solaris is in the works, but he declined to reveal any significant details about the project including what software licence Sun would be using, whether all of the components of the operating system would be open-sourced and when, exactly, Sun intended to release it.

"At this time it's in the development phase," he said. "We're in the thinking about it stage, and looking at details. There are a million details to work out."

The debate over whether or not to open source Solaris has been a contentious one, according to sources within Sun. As recently as Tuesday, Sun CEO Scott McNealy was claiming that it would make little sense for Sun to freely release such a valuable asset.

But Sun has, in fact, released a number of open source software products to date, including the OpenOffice productivity suite, components of the Gnome desktop, and the Tomcat servlet container. However, the company has, until now, declined to release its most important software assets - Solaris and the Java platform - under an open source license.

While the central kernel of the Solaris operating system includes some interesting technology, an open-source Solaris will need to materialise within the next few months if it is to be of any interest to developers, said Eric Raymond, founder of the Open Source Initiative, a non-profit corporation created to help companies develop open source software licenses. "If they don't get this done within six months, it's not going to matter at all because Linux is advancing too fast," he said.

Sun has lost a significant portion of its business to Linux servers running on inexpensive Intel-based systems. Linux server shipments grew by 57 percent year-over-year in the first quarter of 2004, while sales of Unix servers declined by three percent during that time, according to industry research firm IDC.

The fact that Sun is now planning to open source Solaris is somewhat ironic, Raymond said. "It is a matter of record that Linux was written because Solaris was too expensive and was closed source," he said. "If they had open-sourced it in 1990 or sooner, Linux would never have happened."