qt Use EGL instead of default GLX to manage OpenGL contexts on the desktop Add support for exceptions - like catching them inside the event loop (recommended by upstream) Enable dev-libs/glib eventloop support Build a Qt style called GTK+ that mimics the active GTK+ theme Enable the Qt3Support libraries for Qt4. Note that this does not mean you can compile pure Qt3 programs with Qt4. Build the 'trace' graphicssystem engine which allows to record all drawing operations into a trace buffer. Later it can be replayed with the qttracereplay utility https://bugreports.qt-project.org/ http://qt-project.org/doc/