The site definitely was written entirely in OJ=). What you are seeing is that OJ, since it is just JS, can be run server side as well as client side. Server side it generates HTML/CSS (so it renders with JS turned off), but client side it renders directly to the DOM for faster templating, and automatic event binding.

The tool for server side static site generation is available in node npm. You can install it with `npm install -g oj`. Example projects can be found here: https://github.com/ojjs/oj-examples

It's probably pre-compiled