In a GNU/linux distribution is usually installed Xorg as main graphical server, it operates with a client-server logic, a special windows is designate as desktop environment and this special windows can handle all the eyecandy stuff like decorations, icons and effects.

The problem is that the latest UI heavily relies on hardware acceleration, Unity is an overlay on Compiz and the Gnome-shell also require an active driver for the GPU to work well: the problem is:

• on the same OS I can find multiple implementations of OpenGL
• who is handling my OpenGL buffer?
• how the OpenGL buffer is managed compared to the other windows? how can I be sure that my OpenGL implementation is glued to the hardware and is not related to the client-server logic of Xorg?

For example I have tried the clutter library and I have only experienced problems under both Unity and GTK/Gnome, no problem under other OS.