webhelpers.markdown is a copy of Markdown 1.7, used as a fallback for webhelpers.html.converters.markdown() if the full Markdown package is not installed. See the Markdown website for documentation on the Markdown format and this module. Markdown is now at version 2.x and contains new features and plugins which are too big to include in WebHelpers. There is also an alternate implementation called Markdown2. Both are available on PyPI. See the markdown() documentation for how to use them with WebHelpers.