Hi eric, yes that's correct MoI uses the JavaScript language for writing scripts.

But there isn't really any documentation for how to get started, it would probably be a lot easier to get started using Max's node system which is a kind of visual programming mechanism rather than doing regular scripting.

There is a little bit of information about scripting here though:
http://moi3d.com/wiki/Scripting

In the future I do expect to spend some time on scripting documentation and making it easier to get started.

- Michael