Provides R bindings to the Sundown Markdown rendering library by Vicent Marti e.a., based upon work by Natacha Porté. Markdown is a plain-text formatting syntax that can be converted to XHTML or other formats.

The R function `markdownToHTML` renders a markdown file to HTML. Options controlling HTML output and supported markdown extensions can be optionally specified.

The package also exports the underlying Sundown C extension API which enables creating and calling custom renderers using the `renderMarkdown` function.

Please note: the rmarkdown package (with leading r) converts R Markdown documents into even more formats, by using pandoc; the CRAN rmarkdown package is a newer and enhanced version of this markdown package.