You mean the code snippets? That's the default styling that comes with Octopress[1], which the author is using for their blog.

[1] http://octopress.org/

As far as I can tell, the colour theme is solarized dark (http://ethanschoonover.com/solarized), if that is what you are interested it. It's available for quite a few editors (I use it with emacs via `(load-theme 'solarized-dark t)`).

Probably Sublime text. http://www.sublimetext.com/

It is the shit.

It's not a screenshot - Just some CSS :-).