php-markdown 1.6.0-1build1 (amd64 binary) in ubuntu xenial

 This is a library package that includes the PHP Markdown parser and its
 sibling PHP Markdown Extra with additional features.
 .
 "Markdown" is actually two things: a plain text markup syntax, and a
 software tool that converts the plain text markup to HTML.
 .
 The Markdown syntax allows you to write text naturally and format it
 without using HTML tags. More importantly: in Markdown format, your text
 stays enjoyable to read for a human being, and this is true enough that
 it makes a Markdown document publishable as-is, as plain text. If you
 are using text-formatted email, you already know some part of the
 syntax.