How do I install GNOME Shell? [duplicate]

Install the gnome-shell package. You can try it out by pressing Alt+F2 and entering gnome-shell --replace.

EDIT: You can install gnome3-session to allow you to choose GNOME SHELL at login. This is a more robust solution than the following

If you want to permanently switch to the GNOME shell interface, open up a terminal (Applications -> Accessories -> Terminal) and copy and paste this into the teminal:

ln -s ~/gnome-shell/install/share/applications/gnome-shell.desktop ~/.local/share/applications/gnome-shell.desktop && gconftool-2 -s /desktop/gnome/session/required_components/windowmanager "gnome-shell" -t string

See the GNOME Shell website for more details.

Keep in mind that Gnome Shell from the repositories is a snapshot of an early development release. It will stay the same until the next Ubuntu release. If you want to try the latest Gnome Shell and get updates as they happen, you'll need to build it from source. This is made fairly easy if you're willing to play with the terminal :)

There are directions at http://live.gnome.org/GnomeShell#Building You can use wget instead of curl -O, and you should run sudo apt-get build-dep gnome-shell first.

In this case, best to just run it in place (as they explain in that page) instead of installing it.

You can install the gnome3-session package. That will give you an option on the GDM login screen to select between the regular “Ubuntu Desktop Edition” session, and the “GNOME 3” session which will use gnome-shell.

GDM will select whatever session you last used by default, so this is an easy way to switch between the regular Ubuntu environment and GNOME 3/gnome-shell.