JavaScript inheritance library? JS does this by default, no need for more useless boilerplate. The below works in all browsers, IE5 included.

function inherits(child, parent) { function tmp() {}; tmp.prototype = parent.prototype; child.prototype = new tmp(); child.prototype.constructor = child; }

function A() { this.x_ = 5 }; function B() {A.call(this);};inherits(B, A);