It's CSS selectors and then wrapping the DOM element again in a function to give it an `attr` method, which is jQuery style. Other libraries may use that syntax too, but I'm pretty sure it started with jQuery (and if not, was certainly popularized by it).
> return [ $($('h2 a')[0]).attr('title'), $($('h2 a')[1]).attr('title') ];
which are 2 css selectors and picking an element. That is pretty much covered by all of the available http parser libraries