This is the source code behind raw.githack.com.
The idea of this service is inspired from rawgit.com (formerly rawgithub.com). I just realized that using a whole framework (node.js with express.js) for such simple thing as requests proxying is overkilling, and made same stuff using nginx only.
This is also a game: I am trying to implement the same functionality using nginx config files only. No programming languages allowed. Come join me!