"Conventional wisdom among free software and open source developers has long warned that software patents could corrupt and disrupt good software projects. The GPL mentions such a risk, for example. While only a few patents have actually stopped the development of some software (Unisys' GIF patent, the patented LZW algorithm, and Fraunhofer's MP3 patent), the risks involved in developing software in a patent-haunted world remained unclear.
"Though many developers prefer to ignore patents, the current laws (at least in the U.S.) provide minimal legal defense for unwitting infringements. Worse yet, though a project may have pedigreed and documented prior art that could easily convince a court to overturn a patent, the cost of such an action is out of reach for most developers--and many companies..."
