Maker of Framer (http://framer.com) here. Cool to see this popping up on HN. We are a code based interactive design tool, and see many designers use/learn code to experiment with math, real data and physics.
Kudos to Koen and to the whole Framer Team. They are a passionate and outstandingly competent and available crew, which is constantly giving back to the design/coding/makers community. ps> I use your open source tool cactus on a daily basis: https://github.com/eudicots/Cactus!
I love Framer and Cactus. Framer really made me fall for CoffeeScript. Cactus inspired me to build https://github.com/themejuice/tj for WP dev and the corresponding Mac app.