"Unisys might want five kilo-bucks from you. If the program you
used to create GIFs for your Web site employs an unlicensed copy of
the Lempel-Ziv-Welch compression algorithm, then Unisys says you
are guilty of "contributory infringement" on its patent for the
algorithm. Think of it as being an accessory after the crime."
"Developer News spoke to Oliver Picher, spokesman for
Unisys. Picher is in charge of fielding questions about the LZW
"... if you create or distribute software that uses LZW
compression technology in any way, you must deal with the
ramifications of the Unisys patent. As a recipient, user, or
distributor of hardware or software products containing LZW
compression capability, Unisys cautions you to make sure that you
are lawfully acquiring and distributing licensed LZW software."