In Unity 2D desktop you may have both window title-bar and top-panel control when maximizing a window. So that you want to remove the maximized window titlebar.

This can be handled by gconftool. If you have the GUI frontend gconf-edtor installed, just launch it and navigate to “/apps/metacity/general”, then un-check “show_maximized_titlebars” to remove the maximized window titlebar.

Or, you can execute this command in terminal to remove it:

gconftool --type bool --set /apps/metacity/general/show_maximized_titlebars false

Run this to re-enable it:

gconftool --type bool --set /apps/metacity/general/show_maximized_titlebars true