Florian Mueller, who made a name for himself during the campaign to prevent the adoption of software patents in Europe some years ago, said he had dug up a court filing that showed the payment had been made.
"The significance of this finding lies in how it reflects on Red Hat's credibility," Mueller wrote in his blog.
He said in the political and regulatory contexts, Red Hat insisted that open source licences (especially the GNU General Public Licence) were incompatible with payment of patent royalties. "...this simply depends on the specific terms and conditions of a deal," he added.
Mueller said Red Hat used the GPL as a pretext for refusing to offer its customers implementations of patent-encumbered standards such as the AVC/H.264 video codec.
"Another important credibility issue is that the world's largest open source company actually fails to be open about its patent-related dealings and positions, a fact that others have criticized (sic) before," he said.
"It hides behind self-imposed confidentiality obligations and employs legalese terminology that in the eyes of many laypeople will appear far more favorable (sic) to Red Hat than a straightforward representation of the facts would."
Red Hat has been contacted for comment.
Mueller says the payment made by Red Hat was kept secret but news about it surfaced in another suit. (PDF - 450k)
According to him, FireStar Software filed a suit in the US District Court for the Eastern District of Texas in 2006. It was alleging that a patent related to linked databases (US Patent No. 6,101,502) was being infringed by Hibernate, a JBoss product.
At the time that FireStar first approached JBoss, the process of its acquisition by Red Hat had begun. Mueller says that FireStar may have regarded this as "a financial opportunity".
"The patent-in-suit was later assigned to a Texas company named Datatern," he said. "An investment group named Amphion Innovations US, which owns a stake in FireStar and set up its wholly-owned subsidiary DataTern as a patent licensing company (i.e., a non-practicing (sic) entity), also became a party to the suit.