I'm not 100% against Javascript for things like this. It does make it much easier for non-C coders to get involved (although, to be honest, beginning C isn't that hard, and if you're going down this path you should try and learn it anyways).

It's the pretense of putting it all in an HTML document. The point of HTML is not anywhere close to the use case here. Javascript is way beyond its browser origins, why would it still need to be coupled? I can't imagine tossing in an HTML parser simplifies anything either.

Oh the memory though... GC's on embedded devices scare the hell out of me.