The last of Unisys’ patents on LZW (the compression scheme used in the GIF image format), the Canadian one, expires today (July 7th 2004). The US one expired last year; the European ones have been expiring on various dates over the past two weeks.
However, IBM still holds a patent on LZW which expires on the 11th of August 2006. As it covers exactly the same things as the Unisys one, it’s almost certainly invalid, and IBM has certainly never tried to enforce it. Still, sadly, it provides extra fear, uncertainty and doubt.
Still, practically, I expect this means that packages like The GIMP will start shipping GIF modules as standard now. Of course, anyone who hasn’t yet switched to PNG for their website is a muppet. :-)