We have a client who wanted their point-of-sale web application to launch and run in Firefox in 'kiosk' mode, so that it took up the full screen and no browser menus, tabs, etc. showed up on the screen. Internet Explorer has a kiosk mode built in, but Firefox doesn't (the closest it gets is 'full-screen', but some parts of the browser are still visible, although slid partially out of view). I found a Firefox kiosk plugin that looked like it would do what we needed. Ran it through some tests and it looked good:
https://addons.mozilla.org/en-US/firefox/addon/1568
To use it: install the plugin, then restart FF, then go to Tools > Add Ons and find the Full Fullscreen plugin in the Extensions list, click Options, then check 'Fullscreen on startup', check 'Prevent navbar auto-popup' and check 'Hide tab bar', then close the Add Ons dialog. Set your default page to the page you want the browser to launch with, close all pages/tabs and restart the browser. Your default page should load and take up the entire screen.
Our client asked about cookies, since their application uses them to remember a terminalID for the point-of-sale terminal to load. Cookies work normally, since things are just running in the browser, so no problems there.
Note: this doesn't do a lockdown that prevents a user from hitting F11 to toggle between full and regular screen views. Users can hit alt-F4 to close the browser, too. If they do, when they relaunch the browser it will load up in kiosk mode again.
It'd be nice if Firefox had this built-in, but since it's a pretty rare requirement, I can see why it wouldn't be. This plugin filled the gap nicely.
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