Today, the ridiculous patent <a href='http://www.unisys.com' >Unisys</a> has over the <a href='http://dogma.net/markn/articles/lzw/lzw.htm' >LZW</a> compression method commonly used in GIF images expires! The decision a few years ago to enforce this patent and collect royalties was what led to the creation of the superior <a href='http://www.libpng.org/pub/png/' >PNG</a> image format.