RALEIGH – Red Hat is being sued for patent infringement less than two weeks after Microsoft Chief Executive Officer Steve Ballmer fired a verbal shot across the bow of the Raleigh-based Linux software firm.

IP Innovation filed the suit in a Texas court on Oct. 9. It came eight days after Ballmer told a group of developers in London that Red Hat and therefore Red Hat (NYSE: ) clients have infringed on Microsoft’s intellectual property.

“People who use Red Hat, at least with respect to our intellectual property, in a sense, have an obligation to eventually compensate us,” Ballmer said.

Microsoft has been pressuring Red Hat to reach some sort of IP deal, especially since it did convince Novell to form a partnership and reach a ceasefire over software claims.

Interestingly, Novell is also part of the lawsuit in Texas.

“Red Hat’s and Novell’s infringement, contributory infringement and inducement to infringe have injured plaintiffs and plaintiffs are entitled to recover damages adequate to compensate them for such infringement, but in no event less than a reasonable royalty,” IP Innovation said in the complaint.

IP Innovation said the defendants were “deliberate and willful” in their actions and that it wanted an injunction as well as “increased damages and other relief.”

Interestingly, as the Web site Groklaw notes, Brad Brunell, a former general manager for intellectual property at Microsoft, joined Acacia Research Corp., which is the parent of IP Innovation.

Red Hat remains defiant in its stand against Microsoft and said in one of its blogs that customers can continue to “deploy with confidence.

“Our confidence in our technology and protections for customers remains strong and has not wavered,” wrote Red Hat’s IP team.

“Red Hat’s Open Source Assurance protections focus on our clients’ business continuity as well as indemnification against claims raised by any holder of software patents,” they added. “Part of our Open Source Assurance is an intellectual property warranty, a promise by Red Hat to replace its software if there is an intellectual property issue. This provides customers with assurances of uninterrupted use of the technology solution. Protecting our customers is a top priority, and we take it very seriously."

However the blog was apparently written before the news about the Texas lawsuit broke.

“The reality is that the community development approach of free and open source code represents a healthy development paradigm, which, when viewed from the perspective of pending lawsuits related to intellectual property, is at least as safe as proprietary software. We are also aware of no patent lawsuit against Linux. Ever. Anywhere," the company wrote.

The IP Innovation suit is going to be an interesting one to follow. Groklaw, which covered extensively the law suit against IBM by SCO that ultimately failed, calls the new case the “first-ever patent infringement litigation involving Linux.”

What precedent will it set? The entire open source community, let alone Red Hat, could suffer immensely if IP Innovation prevails.