Contributing
This is a collaborative blog, so everyone is welcome (and encouraged) to contribute.
The easiest way to contribute is to simply write a LaTeX or Markup document, and email it to me (preetum [at] berkeley). (Include the .bib file if you use a bibliography, and put all macros into the main tex).
The entire source code of this blog is public on Github, so in theory you can also author a new post by compiling and pushing the appropriate files in the appropriate places. In practice it’s rather messy, but details are here.
We use a LateX to HTML compiler which should work on anything that’s not too fancy. (details of what works is below, but almost everything in math mode should work). Markdown is rendered “natively”.
Writing LaTeX: What works
We use this LaTeX to HTML compiler, which is a modified version of Luca’s LaTeX2WP.
It has support for:

Theoremlike environments: “theorem”,”definition”,”lemma”,”proposition”,”corollary”,”claim”, “remark”,”example”,”exercise”

section, subsection, section*, subsection*

proof environment, and \qed

font formatting: \em, \bf, \it, \emph, \textbf, \textit

Arbitrary mathmode macros. (There are processed by MathJax, so they only expand in math mode).

The following math environments: http://docs.mathjax.org/en/latest/tex.html#environments (including align*, array, bmatrix, cases).

Footnotes (which render inline, collapsible).

Bibliography (input .bbl)

\cite, \ref, \eqref, \label
Working Examples