Focal Point
A small set of CSS classnames to help keep images cropped on the focal point for responsive designs. Using only HTML/CSS, web authors can specify an image's focal point, which stays as the image's primary focus, while the image's available width changes on responsive webpages. Crop and re-size images depending on available width and let CSS to do all of the work, and without any JavaScript.
Lightgallery.js
Full featured javascript lightbox gallery. No dependencies.
FancyBox
FancyBox is a tool that offers a nice and elegant way to add zooming functionality for images, html content and multi-media on your webpages.
Elastislide
Elastislide is a responsive image carousel that will adapt fluidly in a layout. It is a jQuery plugin that can be laid out horizontally or vertically with a pre-defined minimum number of shown images
Flex Slider
An awesome, fully responsive jQuery slider plugin
Joint
JavaScript diagramming library
Beerslider
A vanilla JS keyboard accessible plugin for any before-after comparison
Paper.js
The Swiss Army Knife of Vector Graphics Scripting – Scriptographer ported to JavaScript and the browser, using HTML5 Canvas. Created by @juerglehni & @jonathanpuckey
Raphael
JavaScript Vector Library
Responsive Slides
Simple & lightweight responsive slider plugin (in 1kb)
Ejecta
A Fast, Open Source JavaScript, Canvas & Audio Implementation for iOS
Tremula Js
TremulaJS: Picture Streams + Momentum Engine + Bézier Paths + Multi-Device
Bonsai
BonsaiJS is a graphics library and renderer
jQuery QR Code
qrcode generation standalone (doesn't depend on external services)
Svg.js
A lightweight library for manipulating and animating SVG
Scenejs
An extensible WebGL-based engine for high-detail 3D visualisation
Processing.js
A port of the Processing visualization language to JavaScript.