If i understood well, AnyEvent is made so that one doesn't need to "plug" loops together manually, like you just showed me how to do (thank you!).
I think i'll go for an EV loop, with Gtk2 embedded (or Gtk3 if it works).
My question was very naive : it's the first time in years that i implement a GUI, and the first time that i use events too.
Thank you for reassuring me that Tk and Gtk2 are not slow. I don't remember where i read that Wx was faster, but these words can make newbies like me imagine that not-Wx is bound to be slow.