After that, drag keysnail.xpi and drop it to the Firefox or Thunderbird. Then you can install the KeySnail following instructions. Or from the command line, $ wget https://github.com/mooz/keysnail/raw/master/keysnail.xpi $ firefox keysnail.xpi What’s this? KeySnail allows you to bind functions to key sequences This extension provides very flexible way of customizing the keybindings. You can define