There are two critical lessons for software companies in Airframe Systems, Inc. v. L-3 Communications Corp., No. 10-2001 (1st Cir. Sept. 14, 2011):
(1) It’s not enough to register the copyright in the original source code. When you modify it, register the modified versions too; and
(2) retain copies of all prior versions because you never know which one you might need in an infringement case.
Plaintiff Airframe registered the original software code, then licensed defendant L-3 to use that code. As its clients changed computer systems, Airframe routinely modified its software. When L-3 upgraded its computer system, it got ahold of a newer version of the code and began using it. Airframe found out and sued.
The First Circuit noted that to prove infringement, a plaintiff has to prove both “factual copying” of the copyrighted work and “substantial similarity.” Faced with a summary judgment motion, Airframe put in an affidavit showing how similar L-3’s software was with an updated but unregistered version of the copyrighted software. (The court didn’t explain why Airframe didn’t compare the infringing code to the original, registered code.) The 1st Circuit affirmed summary judgment against Airframe, explaining that Airframe never proved the content of its registered software, so it couldn’t, as a matter of law, establish factual copying.