The next Ubuntu release (9.04, “Jaunty Jackalope”) will see the first set of changes introduced by Canonical’s Desktop Experience Team: The much-discussed notify-osd notification system, and the indicator applet.
While we have worked, and will continue to work with upstreams to get those into official GNOME, this will take a while; those are design/usability experiments, and their full impact and consequences are still to be determined by a large user base, and GNOME rightfully applies their own scrutiny on new things to adopt.
Thus the idea came up to allow both developers and users to be able to choose between the “Ubuntuized” and a more “upstream-like” GNOME experience.
I called that “stracciatella GNOME session”, after the favourite kind of ice cream which is mostly vanilla (GNOME), but with some brown chocolate chips (Ubuntu modifications) in it. Providing a pure “vanilla” GNOME session is currently beyond feasibility, use jh-build if you want to work on pure GNOME.
To enable this feature, apt-get install gnome-stracciatella-session
and select the “GNOME (without Ubuntu specific components)” session in gdm.
In Jaunty, this will suppress the messaging indicator and flip back to the classical GNOME notification-daemon again. I plan to keep stracciatella-session up to date with new developments in future Ubuntu releases as well.