Patent dispute: Red Hat launches an offensive
Red Hat is taking an unusual course of action in its defence against IP Innovation's patent infringement claim. While similar lawsuits are usually carried on quietly and often settled out of court, Red Hat has called on the open source community to help find "prior art." The validity of a patent can be disputed by proving that a patented technology was already in use before the patent was filed (this is called "prior art").
IP Innovation, a company that specialises in buying and enforcing technical patents, took Red Hat and Novell to court in 2007 over a GUI element contained in their respective distributions. The claim is based on US patent number 5,072,412 ("User Interface With Multiple Workspaces for Sharing Display System Objects"), which was granted to Xerox in 1991 and protects the concept of having several workspaces on one display with the possibility of showing a window in multiple workspaces. This has been a standard feature of most window managers running on the X Windows System (X11) which has been incorporated in Unix and Linux desktops for many years.