url - GitHub source dynamic navigation

Question

I was browsing thought GitHub today and noticed that the individual repository navigation doesn't use hash-bangs in the URL /#! or /# and the back button still works. How do you think they are accomplishing this? How does this affect search engine crawling from Googlebot? I know it looks for # in the url.

I'm really quite curious as I know using /# is quite debatable.

Here's an example: https://github.com/mirah/pindah

Thanks!

Answer 1

They blogged about it a while back:

https://github.com/blog/760-the-tree-slider