Some of the NGL demos have now been ported to use Web GL, you will need to enable it in some browsers and not all browsers support it.
The code is written in C++ and converted to JavaScript using the emscripten system. The blog post here outlines how to install and configure emscripten or just follow this the WebNGL demos and core library can be downloaded using bzr branch http://nccastaff.bournemouth.ac.uk/jmacey/Code/WebGL/webngl the demo project each have a makefile that can be used to build the WebNGL.js and WebNGL.data files needed, copy to a webserver with the index.html file and test.
Simple NGL the basic teapot Simple Teapot interacting with JQuery Components
VAOPrimiites simple drawing primitives
Using ngl::lookAt and ngl::perspective utilities
Multiple Views using glViewport
Loading Obj Files and Textures
Using the Abstract Octree Class
Simple Particle System using a Factory Method
Morph Animation using Blend Shapes
Using ngl::Camera
Quaternion SLERP
Multiple Pointlights
Multiple Spotlights
BVH Viewer Demo
Klein Bottle Demo
Textured Cube
Interpolation Demos
Ray->Sphere Collision Detection
Animated Mesh using Assimp
Assimp Loading a Mesh
Bullet Physics Rigid Bodies
Bullet Physics Jenga Demo