If Unity 3D isn't working on your computer and you want to find out if this is because of a bug, because you're using the wrong drivers or because of your computer's hardware, you can use a command which lets you know if your computer can run Unity 3D:
/usr/lib/nux/unity_support_test -p
If you get "yes" for "Unity 3D support", your computer should be able to run Unity based on Compiz (Unity 3D) and according to an AskUbuntu answer, if you get "yes" this most probably means you can run GNOME Shell too because Unity and GNOME Shell have similar hardware requirements.
This command only works on Ubuntu 11.04 or 11.10. If you don't use Ubuntu 11.04 or 11.10, you can check out the Ubuntu-certified hardware list to see if your computer can run Unity 3D (with Compiz).
