These pages are written in MultiMarkdown and published ‘statically’ with some snippets of HTML inserted into each to provide navigation and consistent styling.
MultiMarkdown was chosen for its expressive but simple syntax, including necessary features for academic writing such as bibliographies and mathematics. Mathematics is typeset using MathJax, which I’m not a big fan since it requires server-side rendering; hopefully in a few years we can publish to static MathML. (Remind me to look into TtM or similar when I get a spare moment for this.)
At some point I’ll publish the (very basic) scripts that I use to do this; still iterating them at the moment, however.