Software copyright

Software copyright is the extension of copyright law to machine-readable software. While many of the legal principles and policy debates concerning software copyright have close parallels in other domains of copyright law, there are a number of distinctive issues that arise with software. This article will primarily focus on topics peculiar to software.

Software copyright is used by Software Developers and proprietary software companies to prevent the unauthorized copying of their software. Free and open source licenses also rely on copyright law to enforce their terms. For instance, copyleft licenses impose a duty on licensees to share their modifications to the work with the user or copy owner under some circumstances. No such duty would apply had the software in question been in the public domain.

Copyright protection attaches to “original works of authorship fixed in any tangible medium of expression, now known or later developed, from which they can be perceived, reproduced, or otherwise communicated, either directly or with the aid of a machine or device.”17 U.S.C.A. § 102. Copyright functions by granting the author the right to exclude others. Copyright protects:

+ compilations and derivative works – 17 USC § 103(a).

In the United States, computer programs are literary works, under the definition in the Copyright Act, 17 U.S.C. § 101.

There is a certain amount of work that goes into making copyright successful and just as with other works, copyright for computer programs prohibits not only literal copying, but also copying of "nonliteral elements", such as program's structure, sequence and organization. These non-literal aspects, however, can be protected only "to the extent that they incorporate authorship in programmer's expression of original ideas, as distinguished from the ideas themselves." In Computer Associates vs Altai, the Second Circuit proposed the Abstraction-Filtration-Comparison test for identifying these protected elements. This test attempts to distinguish copyrightable aspects of a program from the purely utilitarian and the public domain.

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