They are mocking the requests for the demos via mockjax.

Yeah, I don't see it either.

I've used pjax with Laravel before, and it's trivial. Kinda does the same thing.

There is a Laracasts video explaining it here: https://laracasts.com/lessons/faster-page-loads-with-pjax

Demo page here: https://pjax.herokuapp.com/

yeah, I mock the ajax requests out so I don't have to host a server-side app

you can click on the code tabs and see what's going on, and it should be easy enough to map to whatever backend technology you are using

Yes. All demos don't send real AJAX requests