How does GitHub change the URL but not the reload? [duplicate]

Question

Hey, I have noticed that when browsing a GitHub repository it uses AJAX to load each folder / file.

I understand all this, I was just wondering how they altered the URL. Can you get and set the URL with JavaScript? If so it could be very useful for bookmarking a section of a JavaScript based website. ( a few pages within one, moved between with JavaScript )

Thanks.

Answer 1

It uses the new push/pop state functions in the history manipulation API.

Answer 2

They described this html5 functionality on their blog here