How does github avoid lag / blink on page load?

Question

When I go to my GitHub control panel, it looks like the page is not reloading, but only the changed content.

So, my first thought was that this is a classic ajax trick, but when I change the content of the page (for example, the title of the change header using the google debugger), which should not reload (as in the ajax hypothesis), and I click on the link, my change is reset, so this part of the page also reloads, BUT it does not blink at all, so how do they do it?

Answer 1

https://github.com/defunkt/jquery-pjax will give you all the magic like a jQuery plugin