Has anyone looked at this project as a way to integrate X11 applications (Gtk / IUP) to the Mac with a native look and feel?
XQuartz
The XQuartz project is an open-source effort to develop a version of the X.org X Window System that runs on OS X. Together with supporting libraries and applications, it forms the X11.app that Apple has shipped with OS X since version 10.5.
quartz-wm
quartz-wm is the window manager used by XQuartz to bring an OS X-like experience to X11 applications. It makes use of the AppleWM X11 protocol extension to have libXplugin within XQuartz render window decoration on its behalf and handles basic window manager functionality as described by the ICCCM.
