Custom Menus is an experimental Firefox extension that can do that – and more. Besides being able to remove menu items in Firefox easily Custom Menus can also rename any Firefox menu instantly. This could be interesting to save some menu space in the toolbars or to make menu entries clearer. That’s a pretty handy thing for users who want to minimize the screen estate taken by menus and toolbars without losing any of the functionality they provide.

Interestingly enough the first level of bookmark folders and bookmarks can be changed and disabled with the Firefox extension as well. The Custom Menu options can be accessed from the Tools menu after installation or by opening the chrome://custommenus/content/editor.xul url in the address bar.

The Firefox extension provides access to three additional parameters that can be changed or added. The extension’s developer missed to provide information for them though which makes it hard to find out what they actually do. The first parameter is called attributes while the second is images. Images can be added by CTRL clicking on the image tab which will open a file browser to load an image.

The second parameter makes it possible to add attributes while the third accepts new styles. It is most likely making use of the default Firefox attribute and style parameters which can be looked up easily on the Mozilla website.

Update: The add-on has been discontinued. The closest alternative feature wise is the UI Tweaker extension.