Paper.js - Open source vector graphics scripting framework that runs on top of the HTML5 Canvas.
Skia - Skia is an easy-to-use and user-friendly 2D Graphics Library that comes with many prominent APIs for usage in software and hardware platforms.
p5.js - JS library for creating graphic and interactive experiences
Cairo - Cairo is an open-source 2D graphics library released under the GNU Lesser General Public License with support for several output devices.
Three.js - A JavaScript 3D library which makes WebGL simpler.
PlotDevice - PlotDevice is a graphics language for tinkerers, designers, developers and is written in Python.