Tiziano Mengotti and Rene Tegel are the lead developers on the GPU project. Mengotti is the driving force behind the license "patch," which says "the program and its derivative work will neither be modified or executed to harm any human being nor through inaction permit any human being to be harmed."
Mengotti says the clause is specifically intended to prevent military use. "We are software developers who dedicate part of our free time to open source development. The fact is that open source is used by the military industry. Open source operating systems can steer warplanes and rockets. [This] patch should make clear to users of the software that this is definitely not allowed by the licenser."
He says some might think an attempt to prevent military use might be "too idealistic" and would not work in practice, but he references the world of ham radio, whose rules specify that the technology is not to be used commercially. "Surprisingly enough, this rule is respected by almost every ham operator."
The developers readily acknowledge that the "patch" contradicts the original intention of the GPL, to provide complete freedom for users of software and source code licensed under it. "This license collides with paragraph six of the Open Source Definition," is how they word it in the license preamble.
Richard Stallman, the founder of the Free Software movement and author of the GPL, says that while he doesn't support the philosophy of "open source," neither does he believe software developers or distributors have the right to try to control other people's activities through restricting the software they run. "Nonetheless, I don't think the requirement is entirely vacuous, so we cannot disregard it as legally void."
"As a pacifist, I sympathize with their goals," says Russ Nelson, a founding board member of the Open Source Initiative (OSI). "People who feel strongly about war will sometimes take actions which they realize are ineffectual, but make it clear that they are not willing to take action which directly supports war."
Tegel says he doesn't fully agree with the inclusion of the clause in GPU's license. "I see the point, and my personal opinion supports it, but I am not sure if it fits in a license," he says. "Like our Dutch military: I can say it is bad because it kills people and costs money. But on the other hand, we were taught by both our leftist and rightist teachers to enjoy our freedom due to the alliance freeing us from Nazis, a thing which I appreciate very much."
Both developers do agree about one aspect of their license clause. It is based on the first of science fiction writer Isaac Asimov's Three Law of Robotics, which states, "A robot may not harm a human being, or, through inaction, allow a human being to come to harm." That, they say, is a good thing, "because the guy was right," Tegel says, "and he showed the paradox that almost any technological development has to solve, whether it is software or an atom bomb. We must discuss now what ethical problems we may raise in the future."