Answering to "why can they change the license after the fact?" , I think the answer is something close to "Licenses can be changed after the fact, provided the

Answering to "why can they change the license after the fact?" , I think the answer is something close to "Licenses can be changed after the fact, provided the owners/maintainers get permission from each contributor, or rewrite the problematic parts". VLC went through a similar transition (from GPL to LGPL); jbkempf's blogposts about this experience may be of interest to you: - http://www.jbkempf.com/blog/post/2012/How-to-properly-relicense-a-large-open-source-project http://www.jbkempf.com/blog/post/2012/How-to-properly-relice... - http://www.jbkempf.com/blog/post/2012/How-to-properly-relicense-a-large-open-source-project-part-2 http://www.jbkempf.com/blog/post/2012/How-to-properly-relice... - http://www.jbkempf.com/blog/post/2012/How-to-properly-relicense-a-large-open-source-project-part-3 http://www.jbkempf.com/blog/post/2012/How-to-properly-relice...