This thread is for the discussion of the GNOME Classic and GNOME Flashback sessions in development only. Please refer to my Precise notes for released versions. Support questions for released versions should be posted in the Desktop Environments section of the forums.
My personal focus is on the Flashback w/Metacity session but I welcome comments regarding the new GNOME Classic and Flashback w/Compiz sessions. No PPA is needed to test the new GNOME Classic session since Ubuntu GNOME Saucy but WebUpD8 still has the best description I've found.
By now most Ubuntu users know that beginning with Oneiric (11.10) Ubuntu switched to GNOME 3/GTK+ 3 as it's base with Unity as the default desktop environment using the Compiz window manager whereas GNOME themselves used the new GnomeShell DE with the Mutter window manager. As a "fallback mode" for hardware that wouldn't support the Compiz window manager Ubuntu offered the Unity-2D session using the Metacity window manager in both Ubuntu Oneiric and Precise but they dropped Unity-2D in Quantal.
GNOME themselves offered a "fallback" session that was presented as "GNOME Classic" which used the Compiz window manager or "GNOME Classic (no effects)" which used the Metacity window manager at login in Ubuntu Oneiric, Precise, and Quantal if the package 'gnome-panel' was installed and, while the GNOME devs never intended to provide long term support for their "fallback session", Edubuntu will continue to maintain the "flashback w/metacity" session in order to support their LTSP installs.
There has however been continued session renaming to facilitate GNOME's new Classic session that runs on top of the Mutter window manager, but the safest and sanest way to install the "GNOME Flashback" sessions in Ubuntu or Ubuntu GNOME is still to install the package 'gnome-panel' which has a very light footprint. Of course if you want to run the Compiz session in Ubuntu GNOME you'll additionally need to install the packages 'compiz' and presumably 'compizconfig-settings-manager'.
There have been a number of changes/improvements since Precise, most notably I had not recommended installing 'gnome-tweak-tool' because it had a very heavy footprint but that's improved greatly, and there have been many changes due to the deprecation of gconf. So after installing 'gnome-panel', logging out, selecting the desired session, and logging back in you may wish to install any of the following packages:
'indicator-applet' and/or 'indicator-applet-session' - as an alternative to 'indicator-applet-complete'
'gnome-tweak-tool' - because it's quite convenient for general theming tweaks such as having the old-style icons appear on the desktop, setting the key sequence for killing X, and changing themes.
'shiki-colors-metacity-theme' - because it provides a rather retro window management button theme
'sensors-applet' - to display system temps
Update notifications now show up in the "window list" applet so no tweak is needed in that regard.
With the ability to add 'gnome-tweak-tool' w/o a bunch of bloat that leaves very few "tweaks" that actually require the use of the CLI:
#1: Moving the window-management buttons back to the right:
#2: Disabling the overlay-scrollbars:
gsettings set org.gnome.desktop.wm.preferences button-layout :minimize,maximize,close
#3: Possibly disabling the Firefox and/or Thunderbird global menu add-ons???????????? I'm unsure about this. I need to play around with fresh profiles and check that out.
gsettings set com.canonical.desktop.interface scrollbar-mode normal
#4: Possibly disabling the Unity webapps:
#5: Restoring the missing menu icons:
gsettings set com.canonical.unity.webapps integration-allowed false
gsettings set org.gnome.desktop.interface menus-have-icons true
gsettings set org.gnome.desktop.interface buttons-have-icons true
The most troubling thing I've encountered is the inability to backup or restore configurations:
Edit: I wanted to add a couple of valuable links: