Look Ma, Just one WebGL Context

generic webgl
generic webgl no size
red
blue
purple with alpha .5 but alpha:false
green .5 with alpha .5 alpha true (default)
green 1 with alpha .5 premultipliedAlpha: false
preserveDrawingBuffer: true
three.js
WEBGL_draw_buffers
ANGLE_instanced_arrays & OES_vertex_array_object
generic webgl2
generic webgl2 no size
red
blue
purple with alpha .5 but alpha:false
green .5 with alpha .5 alpha true (default)
green 1 with alpha .5 premultipliedAlpha: false
preserveDrawingBuffer: true
three.js
multiple render targets
Instanced Drawing & VertexArray
GPGPU