Listing the Fab Four who were AES finalists with Rijndael, I wrote:
Serpent is public domain, now under the GNU PUBLIC LICENSE (GPL), although >Serpent website warns that "some comments in the code still say otherwise." <>http://www.cl.cam.ac.uk/~rja14/serpent.html>
I should have been more careful. Serpent, per se, has been given over to the public domain. What has been released under the more restrictive GPL terms are the optimized Serpent implementations -- by a variety of talented folk, in a variety of useful languages -- which were in the AES submission package. They are now available from the Serpent website at: http://www.cl.cam.ac.uk/~rja14/serpent.html. As the website puts it: "Serpent is now completely in the public domain, and we impose no restrictions on its use. This was announced on the 21st August at the First AES Candidate Conference. The optimised implementations in the submission package are now under the GNU PUBLIC LICENSE (GPL), although some comments in the code still say otherwise. You are welcome to use Serpent for any application. If you do use it, we would appreciate it if you would let us know!" Sorry if I confused anyone. _Vin