ObjFW  GUI framework - call for help!

For option 1 - 4, there needs to be a decision between Gtk and Qt. Here's some thought I have, but nothing is set in stone:

**Pros for Gtk:**

* gobject's object model is inspired by Objective-C, so pretty compatible
* Gtk apps look good on GNOME and KDE (KDE can make it look like a native app), it looks OK on Windows
* Gtk is written in pure C, so we would not need to make sure that our headers contain no C++ (even transitivly)
* There is gobject-introspection that should make it easier to create bindings

**Cons for Gtk:**

* It looks meh on Mac, but is still fully functional

**Pros for Qt:**

* It looks good on Windows, KDE, Mac

**Cons for Qt:**

* It is written in C++ and special care needs to be taken that the GUI framework does not end up with headers that need C++. That means redefining every enum as a C enum and wrapping absolutely every class. It also means often using void pointers and lose type safety.
* It uses multiple inheritance which does not work with the Objective-C object model, so this needs to be hacked around.
* Qt apps still look alien under GNOME, despite some attempts to make that better.

**Open questions for Qt:**

* Is there something like gobject-introspection that can make it easier to create bindings?
Anything else I forgot?