jquip : Smaller, Lighter, Faster, more modular jQuery - include only the parts you want! Don't use it, Don't include it.
Cliquet : Cliquet is a toolkit to ease the implementation of HTTP microservices, such as data-driven REST APIs.
Crafty : JavaScript Game Engine, HTML5 Game Engine
Data Science Toolkit : A collection of the best open data sets and open-source tools for data science, wrapped in an easy-to-use REST/JSON API with command line, Python and ...
emotion : emotion is a high performance, lightweight css-in-js library that supports both string and object based styles.
Sammy is a tiny javascript framework built on top of jQuery, It's RESTful Evented Javascript.
