If you are developing something and haven't got a clue where to start, some of this might be good pointers.
Qwery - find stuff in the DOM https://github.com/ded/qwery
Bonzo - a thing for modifying the DOM https://github.com/ded/bonzo
Bean - an events library for components https://github.com/fat/bean
Reqwest - an Ajax library https://github.com/ded/reqwest
Play - the application server https://playframework.com/
We also have a set of Node dependencies, used mostly by our static asset pipeline. We use npm to manage these.
When you want to add or update a dependency:
npm install <package>@<version> --save
npm shrinkwrap
node dev/clean-shrinkwrap.js