Markdown extensions

A number of lightweight markup languages extend Markdown by implementing added features (such as tables, footnotes, definition lists, and Markdown inside HTML blocks) not available with plain Markdown syntax. In some cases, this is in order to enable conversion into more formats than HTML, for example, LaTeX, RTF, and DocBook.

Many implementations also intentionally omit support for middle word emphasis. The original markdown implementation interprets constructs like my_long_variable as a request to emphasize "long" in the middle of a word. Many users found this confusing, so many later implementations such as PHP Markdown and Python markdown do not implement middle word emphasis by default [1]

Among these are Markdown Extra, MultiMarkdown, Maruku, kramdown and the Pandoc Markdown extension.

The essay "Thoughts on Markdown" stated that Gruber (markdown's original developer) has not responded to discussions about extensions to markdown, and that "Markdown is changing, with or without him".

External links

• PHP Markdown Extra official Markdown Extra site, featuring PHP implementation and syntax reference.
• Maruku is a Ruby implementation of Markdown and Markdown Extra.
• kramdown is another Ruby implementation of Markdown which adds several features inspired by Maruku and Markdown Extra.
• MultiMarkdown is an implementation of Markdown oriented toward writing, which includes various extensions, including footnotes and RTF and LaTeX output.
• Python Markdown is an implementation of Markdown with various extensions such as tables and ignoring internal bold/italic markings.
• Pandoc is a Haskell implementation of Markdown with numerous extensions and additional output formats, including reStructuredText, HTML, LaTeX, ConTeXt, PDF, RTF, DocBook XML, OpenDocument XML, ODT, GNU Texinfo, MediaWiki (Wikipedia) markup, groff man pages and S5 slideshows. The underlying parser reads not only Markdown, but also reStructuredText and subsets of HTML, and LaTeX.
• Showdown is a Markdown parser written in JavaScript.