It’s QtCreator, not just Qt, it’s not the same even if based on Qt.
Since it’s officially supported, with tutorial in the oF download section, this is the easiest one to set up and requires the least work to do so.
Good thing is, even the newest versions like QtCreator 4.11.1 work with OF very well without issues (even though the setup tutorial for OF on Linux is for 4.6.1); tried both 4.6.1 and 4.11.1, doesn’t make much difference - it works just fine.
Don’t know about vscode and atom, considering full code autocompletion. To have it, they would require to recognize openFrameworks project dependencies (for your own OF-based project) - and to do that, they’d have to compile it in real-time, seeing whether you can use some particular OF function and what arguments can it take, how many overloads does it have, etc.
Tried Atom before, but to me, it’s limited to autocompletion of your own project only. It won’t see the functions of openFrameworks you have in the documentation section.