UNIX System Laboratories, Inc. v. Berkeley Software Design, Inc.

The suit has its roots at the Computer Systems Research Group (CSRG) at the University of California, Berkeley, which had a license for the source code of UNIX from AT&T's Bell Labs.

Students and faculty at the CSRG audited the software code for the TCP/IP stack, removing all the AT&T intellectual property, and released it to the general public in 1988 as "Net/1", under the BSD license.

Berkeley Software Design (BSDi) obtained the source for Net/2, filled in the missing pieces, and ported it to the Intel i386 computer architecture.

Rather than narrow down their claim, USL chose to sue BSDi and the University of California, and requested a preliminary injunction on the distribution of Net/2 from both.

[2] In 1993, judge Dickinson R. Debevoise denied a preliminary injunction, on the grounds that USL had no valid copyright over 32V and could not show any obvious trade secret.