The pad was written using browser extension called [GreaseMonkey](https://addons.mozilla.org/en-US/firefox/addon/greasemonkey/) + a [custom user script](https://hub.xpub.nl/chopchop/etherpad_mediafragments_xpub/etherpad_mediafragments_xpub.user.js). This hack is described [on this pad](https://pad.xpub.nl/p/greasemonkey).