Microsoft has unilaterally changed the conditions for the Novell SuSE certificates that it sells to customers.
The move is intended to prevent Microsoft being subjected to the GPLv3 open source licence published on 29 June.
If Microsoft is bound by the GPLv3, it would be forced to provide a royalty-free patent licence to all users, developers and distributors of GPLv3 software.
The phenomenon is referred to as GPLv3 contamination, which Microsoft is trying desperately to prevent.
"Microsoft has decided that the Novell support certificates that we distribute to customers will not entitle the recipient to receive support from Novell, or any other party, nor any subscription for support and updates relating to any code licensed under GPLv3," the company said in a statement on 5 July.
To customers, the move means that the certificate will not offer them support for GPLv3 software.
The move surprised Mark Radcliffe, a partner and software licensing expert at Silicon Valley law firm DLA Piper.
"What is interesting is that Microsoft is reacting to the GPLv3 so quickly," he told vnunet.com.
"They never expressed their concerns. They never said: 'Look, we're going to pull the trigger and pull any GPLv3 code if you put this provision in.' I guess they decided that they didn't like the risk level that they going to take."
Although the Linux kernel itself is unlikely to switch to GPLv3, several components bundled with the kernel to form what is described as Linux have alre ady adopted the new licence.
Over time it is expected that Linux distributions will combine GPLv2 and GPLv3 components.
The certificates in question are part of the partnership that Microsoft and Novell signed in November.
As part of the agreement, Microsoft paid US$240m for 70,000 coupons that entitle the owner to a free multi-year subscription to Novell's SuSE Linux Enterprise Server software.
Technically the certificates entitle the holder to support from Novell. Microsoft merely provides the coupons to the user.
However, the Software Freedom Law Center, a legal group that co-authored the GPLv3 and supports open source developers, claims that Novell is just acting as a clearing house and that Microsoft is the legal distributor of the software.
When the group drafted the GPLv3, it chose not to block the Microsoft-Novell partnership because it believes that Microsoft will end up distributing GPLv3 software.
Novell, meanwhile, responded that it will provide support and updates regardless of Microsoft's changes to the terms and conditions.
The firm stated on a company blog that it will essentially continue to honour the Microsoft coupons under the original terms and conditions, including software components governed by GPLv3.
Legally, however, there remain several open questions. "The whole interaction of how [GPLv3] tries to deal with these certificates is a big legal hairball," said Radcliffe.
"You've got this very unusual contractual provision that is trying to say: 'Yes, we have a contract between you and me. And that guy behind the tree named Microsoft, we're going to try to bind him to this agreement too.
"It's a very unusual provision. A lot of lawyers are scratching their heads about how enforceable it would be."
Radcliffe also raised questions about Microsoft's ability unilaterally to change the terms of the coupons.
Even though Microsoft is claiming that it is entitled to do so under the terms of the Novell agreement, a court could enforce the original agreement if it finds that customers relied on the Microsoft promise in the original terms.
Microsoft fights to prevent GPLv3 contamination
By Tom Sanders on Jul 10, 2007 9:51AM