Unity

Unity is an alternative shell for the GNOME desktop environment, developed by Canonical in its Ayatana project. It consists of several components including the Launcher, Dash, lenses, Panel and indicators.

GCC
Should use 4.6.3:

Python
Should use 2.7 and not 3.2:

Installation
You can install Unity with unity-base/unity-meta ebuild, can be found in the unity-gentoo overlay in layman:

If you experience blocks with regard to x11-libs/qt-* packages, then do:

Usage
You should be starting it via a display manager or by XSESSION=unity variable for startx (ref).

External resources

 * unity-gentoo overlay
 * Overlay unity-gentoo thread on Gentoo Forum
 * Unity article in Arch Linux Wiki