Suppose I develop a useful library and decide to publish it as open source. Some time later I have a business need to do something that wouldn't comply with the open source licence. Am I allowed to do that?
How should I publish the software in a way that I keep ownership and don't block myself from using the library in the future in any way?
Keep in mind that at least in theory, other developers may decide to contribute to my open-source project. Can I specify in a licence that I as the original developer get ownership of their contributions as well? Don't get me wrong here, I'm not trying to be evil and get ownership of other's work - I just want to keep ownership of mine, and if someone posts an important bugfix I could be rendered unable to use the original code unless I use his work as well.