WHEN does one program look and operate so much like another one that it should be considered a copy? Does a copyright allow the owner of a computer program to prevent other companies from marketing programs that can be used the same way by computer users? These questions are at the heart of a series of lawsuits now being heard in federal courts. In one high-profile case, Apple Computer Corporation has sued Microsoft and Hewlett-Packard corporations for copyright infringement, claiming that Microsoft's Windows program and HP's New Wave software are substantially similar to the graphical operating system of Apple's Macintosh computer.
In an another pair of suits, Cambridge-based Lotus Development Corporation has attacked Mosaic Software and Paperback Software, claiming that spreadsheet programs by those two companies are so similar to Lotus's award-winning 1-2-3 program that the programs are, in fact, copies - even though they were written by different people. ``We allege that they set out to copy virtually every aspect of the interface of 1-2-3 and they did it,'' says Tom Lemberg, vice president and general counsel of Lotus.
The user interface is the part of a computer program that controls the way the computer interacts with its user. VP-Planner and Twin are so similar to 1-2-3, Mr. Lemberg says, that an experienced 1-2-3 user can use the programs without ever reading their instruction manuals.
``The name Twin was obviously chosen with a purpose,'' says Lemberg. ``Twin of what?''
A computer program is a series of instructions that a computer follows to accomplish a desired result, like a recipe that a baker follows to make a cake. Before the Lotus and Apple lawsuits, it was widely assumed that companies could write and market their versions of competitor's programs, as long as they didn't copy any of the steps that they were trying to emulate.
Apple's and Lotus's suits are similar to a car manufacturer claiming it has copyright on the concept of a steering wheel or a particular gear-shifting pattern, says Richard Stallman, president of the League for Programming Freedom.
But Lotus's Lemberg disagrees. ``The creation of 1-2-3 was a highly creative act, and the thing has been very successful. If you allow people to just come by and copy that work, what you are doing is allowing them to take a free ride on our company's creation. The act of doing that discourages innovation by allowing others to exploit it for free.''
Most of the rulings in the Apple case have concerned whether a 1985 contract between Apple also covers the program that Apple alleges is in violation of the Macintosh copyrights. The Lotus lawsuits are being tried this fall in federal court in Cambridge, Mass.