Faced with new competitive challenges from Novell, Microsoft and Oracle, Linux seller Red Hat has begun promising protection against intellectual-property lawsuits.

The leading Linux seller quietly slipped the indemnification provision into a question-and-answer page on their Web site after Novell and Microsoft announced a technical and patent partnership last week.

"As with any indemnification provision, if (a customer) were to get sued for intellectual-property infringement over code they got from us, the provision of the indemnification language kicks in," said Mark Webbink, Red Hat's deputy general counsel.

"At that point, we step into their shoes" to handle the legal attack."

Indemnification of open-source software rose to prominence after the SCO Group sued IBM, arguing that it copied proprietary SCO Unix code into open-source Linux against the terms of IBM's Unix license. Then the issue died down -- until recently.

Last week, Oracle Chief Executive Larry Ellison said that his company would provide legal indemnification along with a higher-cost option for its Red Hat Enterprise Linux support subscription.

On Friday, Novell boasted that its partnership with Microsoft means customers need not fear patent lawsuits from Microsoft, an expansion of an earlier promise to counterattack in patent lawsuits regarding open-source software it sells.

The indemnification is a new element to Red Hat's Open Source Assurance program, which guarantees customers that the company will rewrite code found to violate another's intellectual property. Webbink said he believes that earlier pledge is more significant than the indemnification.

"We still think the earlier version of the Open Source Assurance was the far more critical thing, and we'll continue to stand behind that," Webbink said.

But the company decided adding indemnification was worthwhile.

"Our management and board looked at it and said, 'Look, this isn't worth a hill of beans, but if saying it will make people feel better, we'll say it.' We've added it to the program," Webbink said.