ThinkOrSwim chart scripting language

I didn't want to go off topic in the PRC discussion topic so I thought I'd ask this here.

What (computer) language are the ThinkOrSwim chart studies written in? I searched their web site but could not find any reference to it.
I'm new to ThinkOrSwim, but have been using this site to help me with ThinkScript. Hope that helps.
There are a couple of sites that one may want to look at too.