ENCOURAGING SOFTWARE REUSE

Over the last fifteen years, the primary means of legal protection for computer software has shifted from copyright to patent. In this artic le, Professor Mark A. Lemley and David W. O'Brien argue that one unant icipated benefit of this trend may be to encourage software reuse. The y note that computer programmers traditionally reinvent software compo nents, coding each new program from scratch rather than buying and reu sing existing components. This inefficient process operates in stark c ontrast to common practice in other engineering disciplines. Lemley an d O'Brien argue that copyright law encourages reinvention and discoura ges the development of a marker for tradeable software components beca use it allows competitors to appropriate the value of a new software i nvention without payment to the original inventor, but forbids competi tors from copying the computer code implementing that invention. As a result, competitors copy others' inventions and ideas but write their own code to avoid infringing copyright. By contrast, patent protection forces competitors manufacturing any product incorporating the invent ion to obtain a license from the patent owner. Lemley and O'Brien main tain that the trend toward reliance on patent law may lead to increase d licensing of both patented ideas and their implementing code, pallin g the way for an expansion of trading and reuse of software components .