We've always published the scripts for each screencast publicly in the page and included code-blocks so you can follow along. But naturally, sometimes code blocks have typos, or you lose context. What file is this? Does this code come before or after this other stuff?
So, our code blocks got a face-lift: with the exact filename always on top, line numbers, and folded lines to show context. What to see those folded lines? Just click them and they'll expand, a-la GitHub. The code comes from the actual project that was built behind the scenes. So, you're seeing the real thing.
Only new code-blocks have this, and you can see an example in the second half of REST Episode 2 - like in our HATEOAS Linking chapter.
I'm not sure how many people read through the code-blocks now, I'd love to hear if this is helpful.