Functionality and Expression in Computer Programs : Refining the Tests for Software Copyright Infringement

Courts have struggled for decades to develop a test for judging infringement claims in software copyright cases that distinguishes between program expression that copyright law protects and program functionality for which copyright protection is unavailable. The case law thus far has adopted four main approaches to judging copyright infringement claims in software cases. One, now mostly discredited, test would treat all structure, sequence, and organization (SSO) of programs as protectable expression unless there is only one way to perform a program function. A second, now widely applied, three-step test calls for creation of a hierarchy of abstractions for an allegedly infringed program, filtration of unprotectable elements, and comparison of the protectable expression of the allegedly infringed program with the expression in the second program that is the basis of the infringement claim. A third approach has focused on whether the allegedly infringing elements are program processes or methods of operation that lie outside the scope of protection available from copyright law. A fourth approach has concentrated on whether the allegedly infringing elements of a program are instances in which ideas or functions have merged with program expression. This Article offers both praise and criticism of the approaches taken thus far to judging software copyright infringement, and it proposes an alternative unified test for infringement that is consistent with traditional principles of copyright law and that will promote healthy competition and ongoing innovation in the software industry