Through NetLogo 4.1 (since 2.0 or so), we used a custom wiki-type format, with custom code for converting it to HTML for display.
Through NetLogo 4.1 (since 2.0 or so), we used a custom wiki-type format, with custom code for converting it to HTML for display. Now we use Markdown, but old models must be supported, so we convert the old markup to Markdown.