You're in luck. I boiled it down from the slightly more comprehensive version that Backbone uses, annotated here: http://backbonejs.org/docs/backbone.html#sect

You're in luck. I boiled it down from the slightly more comprehensive version that Backbone uses, annotated here: http://backbonejs.org/docs/backbone.html#section-206 http://backbonejs.org/docs/backbone.html#section-206 The main difference being that the Backbone version is also copying "static" properties -- properties defined directly on the parent constructor function -- down into the subclass.