The concept is pretty simple:
But the most important feature of domino.js is probably the possibility to add arbitrarily hacks. A hack is just a function bound to one or more events. This function will be executed in its own scope, and can update properties, call AJAX services, dispatch other events, and a lot more. So basically, it gives a strict and clear place to write all those sh*tty features that were not considered in your original design.