The Preferences is accessible via the Preferences... option in the Gabber menu. It provides a central location for the user to customize various levels of the way Gabber behaves. Options are available to customize logging, the appearance of the roster, the way messages are sent and received by default, among others.
The Interface preferences tab has several options to affect the display of the main window, as well as options to enable spelling and the status docklet.
Gabber can keep a memory of the main window size and position if desired. Note that some window managers will conflict with this memory and may cause the window to not appear exactly in the right position.
The other option available here is whether or not Gabber should display icons on the roster or not.
In addition to being able to manually move the toolbars on the main window around, they can also be disabled. For more information about the main toolbar and the status indicator, see the section called Toolbar in the chapter called Main Window and the section called User Status in the chapter called Main Window.
If this option is enabled, Gabber will attempt to spell check messages while the message is being composed. If the text turns red, the word has been identified to be misspelled. Right click on the word to load a menu with possible words to replace the highlighted one.