Is Sun subverting Linux from the inside?

On the plus side though, the move will make it easier for the vendor to sell to government customers, one of its stated key target markets and one in which many organisations are making open source credentials mandatory. "With the public sector, Sun's ensuring it's not seen on the wrong side of the proprietary/open source divide," Butler explains.

But Ward-Dutton is sceptical of Sun's open source intentions as evidenced by its choice of licensing agreement.

Rather than adopt one of the widely-used and already available licences such as the GNU General Public License (GPL) under which Linux is made available, Sun has fashioned its own. The Common Development and Distribution License (CDDL) is based on the Mozilla Public License and was approved by the Open Source Initiative (OSI) earlier this month.

Unlike the GPL, which stipulates that all code developed and used under the licence must be made publicly available, the CDDL prohibits the release of proprietary code used in any project under its remit.

Goguen explains Sun's rationale. "The problem with the GPL is it's extremely viral and it's not clear how to combine source code using other licences because it all ends up being covered by the GPL," he says.

This situation meant that the vendor was obliged to craft a licence that was "friendly to developers and business and would offer them protections".

"It's about enabling people to build on the developments of others so you can keep the intellectual property yourself if need to. It's a far more liberal licence, which is much more friendly to innovators and business," Goguen adds.

But Ward-Dutton sees it more that Sun is "reacting to pressure from partners and investors to create an alternative foundation environment for open source projects that is more in keeping with making profits".

As such, he views the move as "an attempt to distort the whole open source process and I can't help thinking it will fall flat on its face", not least because, under the CDDL license, "Solaris code won't be able to intermingle with Linux".

As Russell Nelson, an OSI director, points out, however, this inability to swap code is a double-edged sword. "You can turn on the conspiracy machine and it would crank out 'but it keeps OpenSolaris from being subsumed by Linux'. The trouble with that theory is that it also keeps Linux drivers from being incorporated into OpenSolaris," he says.

Butler, meanwhile, sees the creation of CDDL as Sun's attempt to play the open source card, but not give away its crown jewels. "With the CDDL, Sun can portray itself as an open source champion, but still retain complete ownership and control of where Solaris goes," he says.

Not true, argues Goguen, who claims that the OpenSolaris development process will be "less restrictive than other open source communities" as it will have "no specific gatekeeper".

"No one person will decide what goes in, which allows for similar and new innovation. We'll occasionally do a distribution that we'll call Solaris and do testing of new releases and that will most likely include a subset of code from the open source community," he says.

This release will be made available for free, Goguen adds, but customers will pay for support.

As to how successful Sun's decision to open source Solaris will be into the long-term, Butler has mixed feelings. On the one hand, he views the move as broadly positive because it will help the vendor ride the open source bandwagon and gain visibility among public sector organisations. On the other, he thinks it unlikely that broader industry interest in Solaris will be dramatically reawakened.

"Sun is trying to hold on to what it's got and take any new business opportunities coming its way. This is an initiative to maintain the viability of Solaris, but it's unlikely to stop the low-end defection to Linux," he concludes.