Cannon.js is an open source JavaScript 3D physics engine created by Stefan "schteppe" Hedman. Unlike physics engine libraries ported from C++ to JavaScript, cannon.js is written in JavaScript from the start and can take advantage of its features. In a 2013 comparison with Ammo.js, cannon.js was found to be "more compact, more comprehensible, more powerful with regard to its performance and also easier to understand", but did not have as many features.