The Superpowers HTML5 game engine is now open source and available on Github. In the developers own words, Superpowers is:
Superpowers is a downloadable HTML5 app. You can use it solo like a regular offline game maker, or setup a password and let friends join in on your project through their Web browser. It’s great for working together over long periods of time, for jamming over a weekend, or just for helping each other out with debugging!
… not just for making games!
We’ve built the Superpowers Game engine and a bunch of asset editors to make games with TypeScript. But the coolest thing is this: Superpowers itself is actually engine-agnostic. It’s just a piece of software for collaborating on projects and you can extend it with project types and editors.
There is a pretty solid set of tutorials and documents available here should you require more information. You can see a demo of SuperPowers in action in the video below. WARNING!!! Mute your sound, trust me.