made a mini-site for my emscripten pd experiments:
https://mathr.co.uk/empd/#build-cleanroom added some scripts for building in a chroot, so you don't risk potential weird interactions with your main dev system
Updated the Gem example with a spinning [cube] with desktop OpenGL 1.x Fixed Function Pipeline lighting emulated in WebGL by Regal.
Other primitives like [sphere] and [torus] fail due to a bug with GL_QUAD_STRIP, have reported it to the Emscripten port.
[teapot] fails for other reasons (incomplete GLU? something else?), seems to be an infinite loop rather than a simple failure...