Markdown

Markdown is a lightweight markup language that converts plain text into structured HTML using simple punctuation.

John Gruber released Markdown in 2004 to simplify web writing for non-coders and developers alike. It uses intuitive syntax (like # for headers or * for lists) to produce clean XHTML. This standard now powers documentation on GitHub, discussions on Reddit, and static sites via Jekyll. By prioritizing readability, Markdown ensures that a source document remains legible even before it hits a browser.

https://daringfireball.net/projects/markdown/