According to the website Groklaw, Twin Peaks, the company that has come after Red Hat, launched a patent infringement action six months ago. The suit revolves around a Red Hat subsidiary Gluster which makes the Gluster file system. This file system is used by Red Hat Storage Server.
Twin Peaks holds a patent for something called Mirror File System, a virtual file system one that links between two file systems and mirrors them in real time. Gluster file system also provides this functionality.
This is the first time anyone has used the GPL to counter-claim in a patent suit. Red Hat's counter-claim relates to "mount", an utility which it has owned since the year 2000. It is released under the GPL; under this licence, source, including any changes, needs to accompany software which is distributed.
"On information and belief, rather than develop its own source code to create its proprietary software replication products, Twin Peaks copied substantial portions of open source code into those products, including source code originally authored by Red Hat," the counter-complaint reads.
"Among the code Twin Peaks improperly copied was that embodied in the 'mount' program released in util-linux version 2.12a, which Twin Peaks copied into the source code for its own 'mount.mfs' tool. Twin Peaks’ verbatim and near-verbatim copying of open source and Red Hat source code into its “mount.mfs” tool is pervasive and extensive."
Apart from seeking that Twin Peaks comply with the GPL. Red Hat is also seeking damages for the alleged violation and a permanent injunction against the distribution of the allegedly offending products.