I have used Greasemonkey many times and am stepping up to Firefox extension development. Is there a consolidated reference for the variables, functions, and anything else that is available to overlays on browser.xul? Besides gBrowser, I note from the source that there are at least gNavToolbox, gURLBar, and gNavigatorBundle and would like more information about what services they provide. I have looked through the XUL School and XUL Tutorial on MDN, searched MozillaZine, and browsed the Jetpack documentation without finding anything but references to gBrowser. I have also looked at the code snippets referenced elsewhere (e.g.) and found specifics, but nothing that puts all the information together in one place. Is there such a reference?