hey for super user mozilla. Cause my connections sometimes getting suck, I need stopping super long XMlHttpRequest, or GIF. By pressing Shift+esc, and all is done...
No more words,
https://addons.mozilla.org/en-US/firefox/addon/superstop/
SuperStop is very simple: it adds a Shift+Esc shortcut that stops active WebSocket connections, XMLHttpRequests, and any animated images, regardless of the state of the Firefox Stop button. This matches the behavior of the Esc button in versions of Firefox prior to Firefox 20
