[stcredzero]

They built it on top of Squeak. That thing is one of the most straightforward VMs to port. The runtimes execute bit-identical. Years ago they were on 40 different platforms, and I've lost track. It's an incredibly elegant architecture.

[aristoxenus]

That's cool. Should have said "happy" instead of "impressed" -- knowing nothing about the technical side, I was imagining the impact of letting kids program ipods/iphones. They must have loved that.

[jfoutz]

One javascript implementation is the lively kernel, here http://www.lively-kernel.org/

I'd bet there are others.