In Whelan Associates[21] the Third Circuit Court of Appeals was confronted with the question of whether, even if there was no copying of object code or source code, there could be copyright infringement in copying the “overall structure” of a program. The case was one where the alleged infringement was a rewrite of a program in a different computer language. The court concluded that since computer software was classified as a literary work under the Copyright Act and prior decisions held there could be infringement of copyright in a play or book by copying the plot or plot devices when the total “concept and feel” of the alleged infringing work was substantially similar to that of the copyrighted work, the same test should apply to infringement of copyright in computer programs. The defendants argued this conclusion was inappropriate in cases of computer software because the basic premise in copyright law is that copyright should apply only to the expression of an idea and not the idea itself. According to the defendants, the structure of a computer program is by definition an idea rather than an expression. The court, however, dismissed this argument by pointing out that it was possible to write a totally different program to perform the same tasks as both programs performed in the present case. The court thus concluded the detailed structure of a program was part of the expression of an idea rather than an idea itself and upheld a finding of copyright infringement.

Similar reasoning was subsequently used to uphold the copyrightability of menu screens as shown on monitors when a computer was running a particular program as audiovisual works. [22]

Copyright infringement was also found in the unauthorized writing of a computer program to implement a scheme embodied in a copyrighted literary work that had previously been operated manually. [23]

A further development occurred in consideration of whether copyright protection exists for what is known as “microcode”, i.e., the programs embodied in a semi-conductor chip for operating a computer. These had been arguments that in view of the utilitarian nature of such “operations software” it should be treated differently from the prior cases that had dealt with “application software.” However, the first case of this type upheld copyright protection. The judge commented: “the methodology employed in the creation of a microcode is to the court indistinguishable from that employed in the creation of any computer program.” [24]

Early in the 1990’s, the pendulum began to swing as software writers started to complain that the protection being given by the courts was overly broad and was inhibiting new developments. Concern that the “look and feel” test was leading to overly broad protection led, at first, to the adoption of a two-part test assessing intrinsic and extrinsic similarities [25]. In Johnson Controls v Phoenix [26] the court focused on the question of whether the structure, sequence and organization of the alleged infringement was the same as that of the plaintiffs program and in Lotus Dev Corp. v. Paperback Software [27] a different court looked at the flow charts of the parties to determine whether there was infringement.

In 1992 the idea began to take hold that a computer program was in some ways like a play or other literary work in which a variety of possibilities presented themselves for protection from, at the most specific, the actual script to, at the most general, the broad outlines of the plot. Other traditional copyright doctrines, such as the concepts that, in some cases, there could be a merger between the idea and its expression because of the limited ways in which a particular idea could be expressed or that protection would not be afforded to features that were dictated by external requirements, also started to be applied in the computer software field. The advantage of these approaches was that copyright lawyers had already grappled with these issues over many years and if the principles that had evolved in dealing with plays could be applied to computer programs, this should facilitate rapid development of the law.

One of the earliest cases to use such an approach was Autoskill Inc. v. National Educational Support Systems Inc.[28]. In this case, Judge Mechem specifically declined to follow the look and feel cases and stated: