I think that no. GPL permits to keep one's changes private and doesn't force to make them public, that is bad in the case of scientific software. However, it fo

I think that no. GPL permits to keep one's changes private and doesn't force to make them public, that is bad in the case of scientific software. However, it forbids to distribute changes under the terms of other licenses, i.e. non-free, that is good. I believe that an enforcement to share source code should be imposed on provate modifications of open-source scientific software.