In this thread it is discussed if it is legally possible to take on open source project and close its sources. But this seems to refer to someone else's project.
So, my question is: What about my own source? Let's say I release the first version as open source, then I make some changes and I want the code from now on to be closed source.
- Is that possible with me as the original copyright holder (with no one having contributed changes except me)?
- Even if I release my program as open source, I am the copyright holder after all, am I?