gleeBox takes a keyboard-centric approach to navigating the web and provides alternatives to actions that are traditionally performed via the mouse. It is mostly meant for keyboard and command line lovers.
Screencasts and more at http://thegleebox.com.
gleeBox is available as a Chrome, Safari and Firefox extension.
Firefox (outdated): https://addons.mozilla.org/en-US/firefox/addon/59191
Development Version (if you like living on the edge)
Chrome/glee_chrome as unpacked extension (in Developer mode).
Safari/gleeBox.safariextension as a new extension in the Extension Builder.
Firefox (Currently not under development. Help us out!): Drag
FF/gleebox.xpi to Firefox to install.