React : A JavaScript library for building user interfaces
loglevel : Minimal lightweight logging for JavaScript, adding reliable log level methods to wrap any available console.log methods
emotion : emotion is a high performance, lightweight css-in-js library that supports both string and object based styles.
Javascript Sound Kit : The Javascript Sound Kit is a wrapper around the ActionScript Sound Object, it makes it possible to use the Sound Object in Javascript the same way yo...
impress.js : It's a presentation framework based on the power of CSS3 transforms and transitions in modern browsers and inspired by the idea behind prezi.com
nlp_compromise does NLP in the browser. It's a handy, and not overly-fancy tool for understanding, changing, and playing with english. We've also got a modest, though ambitious plugin ecosystem.