Unix System Laboratories - https://en.wikipedia.org/wiki/Unix_System_Laboratories
See also: USL vs. BSDi: https://en.wikipedia.org/wiki/UNIX_System_Laboratories,_Inc.....
See also: USL vs. BSDi: https://en.wikipedia.org/wiki/UNIX_System_Laboratories,_Inc.....
(But I set up a redirect, so now the dotless URL works, too.)