Markdown is a lightweight markup language 
, originally created by John Gruber with substantial contributions from Aaron Swartz, allowing people “to write using an easy-to-read, easy-to-write plain text format, then convert it to structurally valid XHTML (or HTML)”.[1] The language takes many cues from existing conventions for marking up plain text in email. In other words, Markdown is a text-to-HTML conversion tool (for web writers).
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