jQuery Pjax
pushState + ajax = pjax
Ol3
OpenLayers 3
Pikaday
A refreshing JavaScript Datepicker — lightweight, no dependencies, modular CSS
Svg.js
A lightweight library for manipulating and animating SVG
Bootstrap Datetimepicker
Date/time picker widget based on twitter bootstrap
Magnific Popup
Light and responsive lightbox plugin with focus on performance.
Particles.js
A lightweight JavaScript library for creating particles
Page.js
Micro client-side router inspired by the Express router (~1200 bytes)
Backbone Marionette
Make your Backbone.js apps dance with a composite application architecture!
Casper JS
Navigation scripting & testing utility for PhantomJS and SlimerJS
Pace
Automatically add a progress bar to your site. #hubspot-open-source
Scroll Magic
The jQuery plugin for magical scroll interactions.
Sigma
An open-source lightweight JavaScript graph drawing library
Tone.js
A Web Audio framework for making interactive music in the browser.
Vivus
JavaScript library to make drawing animation on SVG