Global Menu (aka AppMenu) is a global menu bar shared by all applications launched on a desktop session. This menu bar is displayed in the top bar of the screen (Unity top panel). This feature is built in particular for users of small screens so that they can gain more screen space.
If you want to disable this feature or remove it completely and make each application displays its own menu bar, then follow these tips:
AppMenu Complete Removal
1. To remove completely AppMenu from Ubuntu 11.10/11.04, open the terminal and run this command:
sudo apt-get autoremove appmenu-gtk appmenu-gtk3 appmenu-qt
Restart now your system.
2. To reinstall and enable Global Menu, run this command:
sudo apt-get install appmenu-gtk appmenu-gtk3 appmenu-qt
Then reboot your system.
AppMenu Partial Removal
- To disable this feature without uninstalling it, use these commands, then reboot:
echo "export UBUNTU_MENUPROXY=0" > /etc/X11/Xsession.d/81ubuntumenuproxy
- To re-enable it, issue this command:
sudo rm /etc/X11/Xsession.d/81ubuntumenuproxy
For Firefox, go to Tools > Add-ons > Extensions and disable Global Menu bar: