Please see the GNOME 3.2 Release Notes (and 3.0 Release Notes) for what is new in this major release of GNOME.

Briefly: GNOME 3.2 includes two desktop modes—standard and fallback. Fallback mode uses gnome-base/gnome-panel and x11-wm/metacity, and is similar in appearance and behavior to GNOME 2. Standard mode uses gnome-base/gnome-shell and x11-wm/mutter, and looks and behaves completely differently from previous GNOME releases. By default, the choice of desktop mode is determined by the system's graphics hardware and drivers (standard mode requires modern 3D graphics capabilities).

There is a quick tour of standard mode's GNOME Shell available on the GNOME website. For an in-depth guide to using GNOME Shell, see the GNOME Shell cheat sheet. GNOME Shell at first may feel alien and limited to an experienced GNOME 2 user. We strongly encourage users to persist and make themselves use it for a few days; those who take the time to get used to GNOME Shell's behavior usually grow to love it and don't want to go back to an old-fashioned GNOME 2-like desktop environment.

GNOME 3.2 obtains user language settings from sys-apps/accountsservice. The language can be set in GNOME from the My Account entry in the upper right corner menu. Alternatively, you can directly edit accountsservice user files. For example, to have user jrandom use British English, you can (as root) edit /var/lib/AccountsService/users/jrandom so it reads the following:

[User]
Language=en_GB.utf8

GNOME 3.2 uses media-fonts/cantarell as its default font. Unfortunately, Cantarell only includes a subset of the extended Latin alphabet. Users of languages whose writing systems are not covered by Cantarell will probably want to switch to another font, such as media-fonts/dejavu:

$ gsettings set org.gnome.desktop.interface font-name 'DejaVu Sans 10'
$ gsettings set org.gnome.desktop.interface document-font-name 'DejaVu Sans 10'
$ gconftool-2 -s -t string /apps/metacity/general/titlebar_font 'DejaVu Sans Bold 10'

GNOME 2 applets cannot be used in GNOME 3.2. Fallback mode allows applets, although some have not yet been ported to the new, gtk3-based APIs. In standard mode, there are no applets at all. Some traditional applet functionality can be replicated using third-party GNOME Shell extensions.

In order to manage fallback gnome-panel settings (either add/remove or rearrange applet positions) one has to hold down the Alt key when clicking on the panel. This opens relevant menu for changing either panel or applet settings.

GNOME Shell developers made a controversial decision to not show any sort of shut down or power off menu by default. The Power Off menu item becomes visible after clicking on the upper right corner menu and holding down the Alt key.

If you need an easily discoverable GUI for shutting down the machine (for example, if deploying GNOME 3.2 in a corporate environment where users are required to turn off their computers at the end of the day), you can install the alternative-status-menu extension. To do so, emerge gnome-extra/gnome-shell-extensions and run

 
# eselect gnome-shell-extensions enable 'alternative-status-menu@gnome-shell-extensions.gnome.org'

GNOME 3 will, by default, suspend a laptop when the lid is closed. If you do not like this behavior, you can change it via the gnome-tweak-tool GUI, or using gsettings from the terminal:

 
$ gsettings set org.gnome.settings-daemon.plugins.power lid-close-ac-action blank

In GNOME 3.2, Nautilus by default no longer manages the desktop, and the ~/Desktop folder is simply treated as a normal folder with files.

If you want to have Nautilus manage the desktop like in GNOME 2, you can change the corresponding setting in the gnome-tweak-tool GUI, or use the gsettings command from the terminal:

 
$ gsettings set org.gnome.desktop.background show-desktop-icons true

GNOME 3.2 standard mode (i.e. GNOME Shell) is incompatible with Compiz.

In GNOME 3, if you have "disable touchpad while typing" selected, the touchpad will be disabled for 2 seconds after a keyboard key is pressed. In GNOME 2, this interval was 500 milliseconds. If you like to disable the touchpad while typing, but prefer the shorter timeout interval like in GNOME 2, you can emerge gnome-base/gnome-settings-daemon with the short-touchpad-timeout USE flag enabled.

GNOME 3 allows setting a custom command for advanced customization of input device settings. For example, suppose that you want to configure your touchpad to enable two-finger scrolling (both vertical and horizontal) and edge scrolling (vertical only). You could do

 
$ cp /usr/share/gnome-settings-daemon-3.0/input-device-example.sh ~/input-device.sh
$ chmod +x ~/input-device.sh
$ gsettings set org.gnome.settings-daemon.peripherals.input-devices hotplug-command ~/input-device.sh

and edit input-device.sh so it ends as follows:

# If the device is a touchpad ...
if [[ -z "${device#*TouchPad*}" ]]; then
	# ... enable two-finger scrolling (vertical and horizontal) ...
	xinput set-prop "${device}" "Synaptics Two-Finger Scrolling" 1 1
	# ... and edge scrolling (vertical only, no horizontal, no coasting) ...
	xinput set-prop "${device}" "Synaptics Edge Scrolling" 1 0 0
fi
# All further processing will be disabled if $retval == 0
exit $retval

If, for whatever reason, you want to completely prevent GNOME 3 from automatically modifying your mouse and touchpad settings (note that this will also prevent custom input hotplug commands, such as input-device.sh above, from modifying mice and touchpads!), you can run the following:

$ gsettings set org.gnome.settings-daemon.plugins.mouse active false

GNOME 3.2 is designed to appear significantly less configurable than GNOME 2. For example, by default there is no easily discoverable GUI for changing the Gtk+ theme. Many configuration settings are hidden, but can still be changed from gsettings (dconf), gconf, or using the gnome-extra/gnome-tweak-tool GUI. Discussion of most of these hidden settings is outside the scope of this guide.

GNOME Shell's behavior can be significantly altered using extensions. Gentoo packages the extensions from the official GNOME repository as gnome-extra/gnome-shell-extensions; there are also numerous third-party developers publishing extensions on various websites.

Gentoo uses eselect gnome-shell-extensions to manage system defaults that control whether extensions installed systemwide (i.e. in /usr/share/gnome-shell/extensions) should be enabled. Newly-installed extensions start out disabled by default.

Defaults managed by eselect gnome-shell-extensions can be overridden on a per-user basis using gnome-tweak-tool, or from the command line using gsettings. For example, to load all extensions with the exception of dock and gajim, a user can run

$ gsettings set org.gnome.shell enabled-extensions \
  '["alternative-status-menu@gnome-shell-extensions.gnome.org", "dock@gnome-shell-extensions.gnome.org"]'

GNOME Shell shows graphical corruption under current versions of x11-drivers/ati-drivers (i.e. FGLRX binary drivers); driver versions 11.8 and below are known to be affected. As a workaround, you can force GNOME to start in fallback mode (see Troubleshooting section below), or alternatively, switch to open-source drivers.

If using open-source AMD / ATI drivers, media-libs/mesa should be built with USE=gallium, otherwise GNOME will only run in fallback mode.

Under some versions of x11-drivers/nvidia-drivers, GNOME Shell system tray shows graphical corruption (all icons are rendered identically). This problem is fixed in driver versions 280.13 and newer.

All versions of x11-drivers/nvidia-drivers are incompatible with GNOME's color management support. This is GNOME's color management code relies on XRandR, and NVIDIA's support for XRandR is currently incomplete. There is no workaround at this time.

As reported in bug #375615, for some people, certain versions of x11-drivers/nvidia-drivers (275.28, 280.13, and 285.03 are known to be affected) cause some Gtk+ applications to hang when terminating. One effect of this is to make GDM freeze after the password has been entered; similarly, GNOME will freeze when logging out. The affected versions of nvidia-drivers have been masked. To prevent this problem, make sure to use an unmasked driver version, for example 275.09.07 or 285.05.09.

This is may be caused by a GNOME Shell crash. Try rebuilding gnome-base/gdm with the gnome-shell USE flag disabled.

This is caused by a bug in x11-drivers/nvidia-drivers. See Video card compatibility section above.

GNOME will start in fallback mode if it detects that the graphics hardware and drivers are insufficiently capable. To see a more detailed explanation of why GNOME does not start in standard mode, run /usr/libexec/gnome-session-check-accelerated-helper:

$ /usr/libexec/gnome-session-check-accelerated-helper
gnome-session-is-accelerated: No hardware 3D support.

To force GNOME to start in fallback mode (e.g. due to poor performance or personal taste), open System Settings (or gnome-control-center from the terminal), go to System Info → Graphics, and turn on Forced Fallback Mode. Alternatively, from a terminal:

$ gsettings set org.gnome.desktop.session session-name gnome-fallback

Out of the box, Epiphany 3 cannot load www-plugins/adobe-flash because the browser links to Gtk+-3 while the plugin links to Gtk+-2. On amd64, there is a workaround: if you emerge adobe-flash with USE=-64bit, the plugin will be called through www-plugins/nspluginwrapper, avoiding incompatibility between Gtk+ versions. On x86, unfortunately there is no good workaround at this time; we suggest using a gtk2-based browser (such as www-clients/firefox or www-clients/chromium).

Support for the G_CONST_RETURN macro was formally deprecated in dev-libs/glib during the GNOME 3.1 development cycle. However, some GNOME 2 and 3.0 packages use the deprecated macro and pass -DG_DISABLE_DEPRECATED (or a similar define) to the compiler in their configure scripts or makefiles. As a result, when building against >=dev-libs/glib-2.29.8, such packages will fail with error messages similar to the following:

In file included from /usr/include/pango-1.0/pango/pango-script.h:138,
                 from /usr/include/pango-1.0/pango/pango-gravity.h:98,
                 from /usr/include/pango-1.0/pango/pango-types.h:91,
                 from /usr/include/pango-1.0/pango/pango-font.h:26,
                 from /usr/include/pango-1.0/pango/pango-attributes.h:25,
                 from /usr/include/pango-1.0/pango/pango.h:25,
                 from /usr/include/gtk-3.0/gdk/gdktypes.h:37,
                 from /usr/include/gtk-3.0/gdk/gdkapplaunchcontext.h:31,
                 from /usr/include/gtk-3.0/gdk/gdk.h:33,
                 from /usr/include/gtk-3.0/gdk/gdkx.h:30,
                 from eggdesktopfile.c:34:
/usr/include/pango-1.0/pango/pango-language.h:37: error: expected '=', ',',
';', 'asm' or '__attribute__' before 'char'
/usr/include/pango-1.0/pango/pango-language.h:41: error: expected '=', ',',
';', 'asm' or '__attribute__' before 'char'

Any packages failing in this manner should be reported in Gentoo bugzilla so that they can be fixed.