Oh, silly me, I can actually do this with QDockWidget, never mind :)

QDockWidget dosn’t work like the screenshots you posted – unfortunately. You cannot tabify floating windows like in photoshop/indesign or gimp.

I’m in search for such widgets too, but unfortunately I didn’t find any yet.

So maybe I should un-solve the thread, hopefully someone will respond, if not I may try to do it myself and contribute it, but if you beat me to it – even better, you do seem to be far more experienced, I am a little over six months in programming :)

Hm, the end is open. We’re undecided in the project on how to proceed, maybe we end up with our own implementation too. I’ll have to check if it’s ok to release it LGPL then.