I’d start them on Processing - it gets people programming very quickly with no extraneous stuff like that. And a huge plus: the IDE is dead simple and requires absolutely no fiddling to get up and running quickly (it even bundles the Java installation so you never have to worry about it), and sketches export to applets/applications with a single click. Once you outgrow it, it’s very easy to transition to real Java, far easier than it is to transition from Javascript.
