"I want to do this with pure JavaScript, not jQuery."
"How do I do this with raw JavaScript?"
"I don't like to use libraries, I like to use vanilla JavaScript."
Enough! Using a library like jQuery (or Closure or MooTools or...) is using plain/vanilla/raw/pure JavaScript. (I mean, unless you're using CoffeeScript, TypeScript, Dart, or other such languages.) Using a library doesn't change the language you're using.
jQuery is a library, not a language. You don't write things "in" jQuery. You write things with jQuery, in JavaScript. Or with MooTools, in CoffeeScript. Or with Closure, in Dart. You get the idea.
If you want to do things in the browser without a browser library, what you're doing is using the DOM API directly. Which is to say, writing with the DOM API, in (choose your language, probably JavaScript).
This isn't just a rant about prepositions. (It is a rant, but not just a rant.) It's about understanding what you're using, and how.