SciTech

Speaker faults GPL for

Also on Thursday, before Stallman?s lecture, Harvard law professor Greg Vetter spoke to a small audience in Newell-Simon Hall. His presentation?s title: ??Infectious? Open Source Software: Spreading Incentives or Promoting Resistance??
Vetter is a vocal advocate of open-source software (OSS); he shares the common perception that it is cheaper and less buggy than closed source. But his presentation emphasized the difference between OSS and the ?free software? protected by the GNU GPL, a system free-software advocates refer to as ?copyleft.? While Vetter supports ?99.5 percent of the GPL,? he is vocally opposed to one particular aspect: its restrictions on derivative works.
U.S. copyright law, said Vetter, is designed to protect the rights of creators by restricting certain actions on the part of the consumer: namely reproduction, the creation of derivative works, distribution, and public performance or display. For example, a person who buys a John Grisham novel is not allowed to make a Xerox copy of the book, because its copyright statement forbids any unauthorized reproduction.
OSS uses copyright?s restriction on reproduction to keep its source code open. As the copyright holder, a programmer has the right to forbid certain kinds of copying of his work. Open source licenses simply forbid any copying that would be used in closed-source programs.
Free-software licenses take advantage of the second copyright restriction as well as the first. Paragraph 2b of the GNU GPL states: ?You [the licensee] must cause any work that you distribute or publish, that in whole or in part contains or is derived from the [protected work] or any part thereof, to be licensed as a whole at no charge to all third parties under the terms of this License.? In other words, the GPL forbids the creation of any derivative work that would be used in a closed-source program. This is what Vetter calls the ?infectious? part of the GPL.
Why is this clause so worrisome? Vetter offered some examples of products which might be considered derivative works, if they were ever tested in court. For instance, any program written for the Linux operating system which contains calls to system routines (such as the ones for displaying text on the screen) can be called ?derivative.? When Linus Torvalds released Linux under the GNU GPL, therefore, he wrote in an exemption for system calls.
Kernel-mode device drivers are another kind of software threatened by paragraph 2b. These programs in some sense become part of the Linux kernel in order to do their jobs; if the aggregate is perceived as a ?derivative work,? then all its parts ? including the device drivers themselves ? are legally bound to release their source code under the GPL.
So the GPL spreads itself across the software landscape, ?infecting? what it touches. In response, Vetter said, there has been a significant backlash in the commercial world. Scared of losing their code to the careless inclusion of a GPL?d tool or library, some companies, including Microsoft, have taken to including an ?anti-GPL clause? in their own licenses, forbidding the inclusion of that code in any project which might be affected by the GPL. Vetter claimed that this kind of antagonism can only bode ill for the software industry; what purpose does it serve to create open software if other developers won?t use it?