The Art of Computer Typography
This blog post is pretty light.  If you really care about Knuth's work on METAFONT then you should just read the source code.  It's written using WEB: <a href="http://www.tex.ac.uk/ctan/systems/knuth/dist/mf/mf.web" rel="nofollow">http://www.tex.ac.uk/ctan/systems/knuth/dist/mf/mf.web</a><p>WEB is a language created by Knuth that supports his notion of literate programming.