HTML (HyperText Markup Language) is a markup language. That means it's a language for specifying structure and content of a hypertext document. You can not use it to express algorithms, so it's not a programming language. Whoever thinks writing HTML code is programming really needs a reality check. PHP or JavaScript are an entirely different topic, those are "real" scripting or programming languages, that happen to be used in combination with or in addition to HTML for the simple reason that HTML doesn't do anything.
UnrealScript on the other hand is a programming language or, if you don't want to see it as a full-blown programming like C++ or Java, a scripting language. You use it to put algorithms into a format the Unreal Engine can understand.
woah woah, I never said it was not a full blown programing language, what I said was its as simple as HTML for some things.