Mambot josMarkdown is based on PHP Markdown Extra. Markdown is a text-to-HTML conversion tool for web writers. Markdown allows you to write using an easy-to-read, easy-to-write plain text format, then convert it to structurally valid XHTML (or HTML). “ Markdown” is two things: a plain text markup syntax, and a software tool that converts the plain text markup to HTML.-Mambot josMarkdown is based on PHP Markdown Extra. Markdown is a text-to-HTML conversion tool for web writers. Markdown allows you to write using an easy-to-read, easy-to-write plain text format, then convert it to structurally valid XHTML (or HTML). “ Markdown”　is two things: a plain text markup syntax, and a software tool that converts the plain text markup to HTML.