In line with the other list here that lists closed source projects that have decided to open source their code, this list is for the opposite: open source projects that decided to close source their code.
If you know of any, please add: its name and URL if you know it, what type of software is it, some proof that they were not open source from the start (such as a link about them going open source.)
- Global File System: originally GPL'd → proprietary in 2001(?) → re-GPL'd in 2004. reference