Thomas Fuchs offers a JavaScript powered application that allows developers to filter down to find the most appropriate JavaScript micro-library or micro-framework for their project. There has been an explosion of mini-libraries in the JavaScript world as web developers get to grips with more complex and rich user interfaces and web applications.
A clever hands-on interactive mini-course by Nathan Whitehead that guides you through bite-sized chunks from variables, to functions, to return values, to functions as first-class objects and right into closures and finally continuations. The hands-on exercises are JS Linted and unit-tested which gives you ample space to try out your new-found knowledge.