Each example consists of a complete small LaTeX document shown within the page like this:
Japanese examples look like:
% !TEX platex
\documentclass{jsarticle}
\begin{document}
テキストの例。
\end{document}
See also the examples in The Japanese specific section of the site
English example:
\documentclass{article}
\usepackage[T1]{fontenc}
\begin{document}
Example text.
\end{document}