Compared to most languages, JavaScript is very minimal: It has first-class functions, but only rudimentary support for functional programming. And it has prototypes, but almost nothing else. This can be liberating, as it doesn't force a heavyweight paradigm on you, and if you want something more sophisticated, you can build it yourself. In this talk, we'll explore how to build a programmable object system in JavaScript. We'll look at some of the ideas that have proven themselves in the last 40 years, and we'll also look forward at some of the ideas that are ripe for invention.