What is Chrome?
Chrome is the user interface parts of the application window that are outside of a window's content area.
Toolbars, menu bars, progress bars, and window title bars are all examples of elements that are typically part of the chrome.
Chrome Registration
A supplier of chrome for a given window type (e.g., for the browser window) is called a chrome provider. The providers work together to supply a complete set of chrome for a particular window, from the images on the toolbar buttons to the files that describe the text, contents and appearance of the window itself.
There are three basic types of chrome providers:
What you can do with Chrome
Here are the following examples of what you can do with Chrome:
http://developer.mozilla.org/en/docs/Creating_toolbar_buttons http://developer.mozilla.org/en/docs/Creating_a_Firefox_sidebar
Resources
Configurable Chrome by Benjamin Smedberg <benjamin@smedbergs.us>
http://www.mozilla.org/support/firefox/tips
http://developer.mozilla.org/en/docs/Working_with_windows_in_chrome_code