Chrome has a strict MIME type checking, which prevents files served as text/plain being executed as JS. As such, serving the js from raw.github.com doesn't work.
Um, I'm talking about the web demonstration at http://patriciopalladino.com/files/hieroglyphy/ which embeds the js from the url https://raw.github.com/alcuadrado/hieroglyphy/master/hieroglyphy.js
Thanks for reporting this, and thanks @kernelsmith for taking a look at it. I fixed it by serving the script from the github page.