Yes. People do copy. You'd be lucky to even find attribution. This is one of the things which open source contributors need to make peace with. The way I look at it, the original grew out of my own experiences in my head and that can't be copied. As for manifestations... The more pretty / functional code and sites there are, the better!
A tip from over ten years of FOSS : never try to track your FOSS code, nothing good can possibly come of it