Javascript, CSS3, SVG
http://julian.com/research/velocity/
https://github.com/tictail/bounce.js
https://visionmedia.github.io/move.js/
http://www.createjs.com/demos/tweenjs/tween_circles
https://github.com/daniel-lundin/snabbt.js
http://ianlunn.github.io/Hover/
http://daneden.github.io/animate.css/
http://www.themaninblue.com/experiment/Blobular/
Raphael
http://raphaeljs.com/
http://cancerbero.mbarreneche.com/raphaeltut/
Two.js:
https://jonobr1.github.io/two.js/examples/
http://code.tutsplus.com/tutorials/drawing-with-twojs--net-32024
Sketch/path animation:
https://maxwellito.github.io/vivus/
http://lazylinepainter.info/
D3:
http://bl.ocks.org/mbostock/4339083
http://bl.ocks.org/mbostock/1093130
http://bl.ocks.org/mbostock/6081914
http://bl.ocks.org/mbostock/3087986
Drop shadow:
http://bl.ocks.org/cpbotha/5200394
2000 D3 demos:
http://techslides.com/over-2000-d3-js-examples-and-demos
Newton's cradle:
https://gist.github.com/ZJONSSON/1706523
http://bl.ocks.org/ZJONSSON/raw/1706523/
Three little circles:
http://bost.ocks.org/mike/circles/
SVG defs:
http://tutorials.jenkov.com/svg/defs-element.html
SVG Inkscape and D3:
http://bl.ocks.org/explunit/5988971
SVG Paths and D3:
https://www.dashingd3js.com/svg-paths-and-d3js
D3 tutorials:
https://github.com/mbostock/d3/wiki/Tutorials
Drag D3 circles:
http://duspviz.mit.edu/d3-workshop/transitions-animation/
D3 easing:
http://bl.ocks.org/mbostock/248bac3b8e354a9103c4
http://bl.ocks.org/hunzy/raw/9929724/
D3 bouncing balls:
http://bl.ocks.org/atul-github/0019158da5d2f8499f7f
D3 API reference:
https://github.com/mbostock/d3/wiki/API-Reference
D3 transitions tutorial:
http://blog.visual.ly/creating-animations-and-transitions-with-d3-js/
Physics: http://wellcaffeinated.net/PhysicsJS/
105 Animation Examples:
https://react.rocks/tag/Animation