Computer Associates International, Inc. v. Altai, Inc., 982 F.2d 693 (2d Cir. 1992) is a decision from the United States Court of Appeals for the Second Circuit that addressed to what extent non-literal elements of software are protected by copyright law. The court used and recommended a three-step process called the Abstraction-Filtration-Comparison test. The case was an appeal from the United States District Court for the Eastern District of New York in which the district court found that defendant Altai's OSCAR 3.4 computer program had infringed plaintiff Computer Associates' copyrighted computer program entitled CA-SCHEDULER. The district court also found that Altai's OSCAR 3.5 program was not substantially similar to a portion of CA-SCHEDULER 7.0 called SYSTEM ADAPTER, and thus denied relief as to OSCAR 3.5. Finally, the district court concluded that Computer Associates' state law trade secret misappropriation claim against Altai was preempted by the federal Copyright Act. The appeal was heard by Judges Frank Altimari, John Daniel Mahoney, and John M. Walker, Jr. The majority opinion was written by Judge Walker. Judge Altimari concurred in part and dissented in part. The Second Circuit affirmed the district court's ruling as to copyright infringement, but vacated and remanded its holding on trade secret preemption. Background of the case Computer Associates (CA) created a job scheduling program called CA-SCHEDULER which sorts, runs, and controls the various tasks (jobs) given to a computer. This scheduler was designed to be compatible with IBM System 370 computers which ran any of three different IBM mainframe operating systems: DOS/VSE, OS/MVS, and VM/CMS. Traditionally, a program must be specifically compiled to run on a designated operating system. In order to allow the same code to run on the different operating systems, the CA-SCHEDULER included a component called ADAPTER that was designed to translate the language of the program into commands understandable to that particular operating system. This way the CA-SCHEDULER could use the same code but run on different operating systems. In 1982, Altai established their own job scheduler called ZEKE written for the VSE operating system. In efforts to create a version of ZEKE to run on the MVS operating system, Altai employee James Williams recruited his longtime friend Claude Arney, an employee of Computer Associates, to create the MVS version. Williams claims that at the time he did not know about the ADAPTER component or that Arney had familiarity with the CA-SCHEDULER and ADAPTER code.