A small software company on Wednesday filed a lawsuit against open source distributor Red Hat and several vendors that sell Red Hat products, claiming that Red Hat's JBoss middleware violates one of its patents.

In court papers filed in U.S. District Court for Eastern Texas, Software Tree claims that JBoss infringes its patent on database systems and methods "for exchanging data and commands between an object-oriented system and a relational system."

Software Tree claims the patent in question, U.S. Patent No. 6,163,776, was awarded in December of 2000.

Red Hat acquired open source developer JBoss in 2006 for $420 million. Software Tree contends that certain of Red Hat's JBoss products, including the JBoss Enterprise Application Platform, which includes JBoss Hibernate, step on its patent.

"The infringing products have no substantial noninfringing uses," Software Tree says in court papers. The lawsuit also names Dell, Hewlett-Packard, and Genuitec as defendants because the companies sell JBoss-based software or include it on their products.

According to its Web site, Software Tree specializes in "providing superior software infrastructure that shifts the application/database integration paradigm." Products include the JDX and NJDX object-relational mapping tools.

Software Tree's partners include Microsoft, IBM, Borland, and Sun, while customers range from Concert Communications to the Los Alamos National Lab and News Corporation's Kesmai unit.

The company was founded in 1997 by software industry veteran Damodar Das Periwal.

Software Tree is seeking unspecified damages and is asking the court to issue an injunction that would stop the alleged patent infringement. It also is seeking a jury trial.

The U.S. District Court for Eastern Texas is frequently the site of patent actions as it's seen as having rules favorable to plaintiffs. The court was the venue for IBM's patent dispute with Amazon, which was ultimately settled before going to trial.

Red Hat, Dell, HP, and Genuitec have yet to file formal responses to Software Tree's claims.