Hi, I've been meaning to ask this for quite a while, but I haven't found the time to sit down and actually write something.
As part of my research, I'm writing a program that I think will be useful to other people in the astronomical/astrophysical community. I want to license this program under the GPL, but I still have to sort some details out, namely, I need to find out if I'm allowed to license this under the GPL, taking into account that I've been using a great deal of resources from my University. The other detail is something that's been bugging me and is the reason for this email... Up to a certain degree, I'm sure some people will have interest in extending and modifying the program for their own research. Let's say some research group finds my codebase useful, and extend it into a direction I haven't had the time to work on, or just didn't occured to me was possible. If this is done by one person, in the privacy of their own computer, that's ok, they don't have to publish the modifications. If this person publishes a paper based on my work and his modifications, that's ok, too, he doesn't have to publish the modifications. But what if this person gives copy of the modified sources (or binaries) to a colleague... in the same research group? Is that "internal use"? Does that qualify as redistribution? I think it does, I just want a confirmation. Even further, if the group (Foo Bar et al) publishes a paper for which the modified program was used, can I demand the changes to be published, based on the fact I would have evidence (because of the "et al") the program was redistributed? (I admit it wouldn't be hard evidence) I'm just trying to make this program free software, and prevent the usual abuse that I've seen on the "scientific community" at the same time... (everyone is willing to publish papers, but almost noone is willing to publish source code -- and some papers are worthless without access to the programs used to perform the simulations, but yet they are published) Marcelo