Software patents do not cover entire programs; instead, they cover algorithms and techniques--the instructions that tell a computer how to carry out a specific task in a program. Thousands of instructions make up any one computer program. But whereas the unique combination of algorithms and techniques in a program is considered an ``expression'' (like a book or a song) and is covered by copyright law, the algorithms and techniques themselves are treated as procedures eligible for patenting.
The judicial basis for this eligibility is tenuous at best. U.S. law does not allow inventors, no matter how brilliant they are, to patent the laws of nature, and in two Supreme Court cases (Gottschalk v. Benson, 1972, and Parker v. Flook, 1978) the Court extended this principle to computer algorithms and software techniques. But in the 1981 case Diamond v. Diehr, the Court said that a patent could be granted for an industrial process that was controlled by certain computer algorithms, and the Patent Office seems to have taken that decision as a green light on the patentability of algorithms and techniques in general.
Software patents are now being granted at an alarming rate--by some counts, more than a thousand are issued each year. Unfortunately, most of the patents have about as much cleverness and originality as a recipe for boiled rice--simple in itself but a vital part of many sophisticated dishes. Many cover very small and specific algorithms or techniques that are used in a wide variety of programs. Frequently the ``inventions'' mentioned in a patent application have been independently formulated and are already in use by other programmers when the application is filed.
When the Patent Office grants a patent on an algorithm or technique, it is telling programmers that they may not use a particular method for solving a problem without the permission of the idea's ``owner.'' To them, patenting an algorithm or technique is like patenting a series of musical notes or a chord progression, then forcing composers to purchase a ``musical sequence license.''