Paper.js - Open source vector graphics scripting framework that runs on top of the HTML5 Canvas.
LeoCAD - LeoCAD is a CAD program for creating virtual LEGO models.
p5.js - JS library for creating graphic and interactive experiences
LDraw - LDraw is an open standard for LEGO CAD programs that allow the user to create virtual LEGO models...
Three.js - A JavaScript 3D library which makes WebGL simpler.
LDCad - LDCad is a multiplatform ...