Wow, the UI on that is gorgeous. I noticed a trend to add features and capability to GitHub which makes a lot of sense because it must have something like millions of users by now and it's something many of here personally use. I'm also working on something for GitHub (a work in progress, http://gitify.me - better notifications). I think we're going to see a lot of growth in the ecosystem around GitHub and tools. Using git and GitHub is going to become more important as time passes by.

For Prose, the front-end architecture makes a great deal of sense, and they must be using a proxy to get around same origin on API requests. I think some server side operations for caching might make sense to enable speed and reduce the number of requests on GitHub.