So I had a slight problem with my personal page repo on Github. I had pushed a set of commits, which included a submodule (HTML5 Boilerplate). But the site wasn’t building. I contact Github support, and after two emails, the problem is solved! It’s either a problem with their build system and http:// URLs of submodules, or something specific to HTML boilerplate, but after changing the URL to use git:// and pushing, my site was successfully rebuilt. Yay.
Now if I can figure out how to run node on cloud9, I can start messing around with things even more.