The same thing happened with .GIFs, royalties weren't actively pursued for a very long time, but when they were it became a problem.
Let's not make the same mistake again.
Let's not make the same mistake again.
--Unisys 1995 (http://web.archive.org/web/19981203000955/http://lpf.ai.mit....)
Unisys has frequently been asked whether a Unisys license is required in order to use LZW software obtained by downloading from the Internet or from other sources. The answer is simple. In all cases, a written license agreement or statement signed by an authorized Unisys representative is required from Unisys for all use, sale or distribution of any software (including so-called "freeware") and/or hardware providing LZW conversion capability (for example, downloaded software used for creating/displaying GIF images).
--Unisys 1999 (http://web.archive.org/web/20021203075728/http://www.unisys....)