FireStar Software has filed a claim against Linux vendor Red Hat for an alleged patent infringement in one of its software products. 

The disputed patent describes a model for 'employing a relational database with object oriented software'. FireStar alleges that Red Hat's Hibernate 3.0 product infringes on the patent, and is demanding unspecified damages.

The case was filed on Monday in the Eastern District of Texas. A Red Hat spokesman told vnunet.com that the company is aware of the situation and working on a resolution.

Red Hat acquired the Hibernate product last month when it purchased JBoss. The application is an object/relational persistence service that offers similar functionality to FireStar's product. The application is governed by the GNU Lesser General Public Licence. 

The case could turn out to be a first test for several anti-patent shields put up by open source providers over the past year.

The Open Source Development Lab launched the Patent Commons project last year that aims to help developers avoid infringing on patents. 

Numerous patent holders, including IBM, Novell, Red Hat and Sun Microsystems, have pledged not to use their patents against open source projects, although some pledges are more limited in their scope than others.

But anti-patent activist Florian Mueller dismissed the OSDL project as a "placebo initiative".

"Depending on how the FireStar suit evolves, Red Hat may have to answer the question of whether it grossly overstated the benefit of those initiatives to open source developers and users," he wrote on his blog. 

"Apparently, the patent projects supported by Red Hat have not really discouraged FireStar from suing."

A PDF document with the complaint and a description of the disputed patent is available on the Patently O blog.