• Daring Fireball: Markdown
  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).
  in Public bookmarks with html markdown markup text by 9 users
• reStructuredText
  reStructuredText is an easy-to-read, what-you-see-is-what-you-get plaintext markup syntax and parser system. It is useful for in-line program documentation (such as Python docstrings), for quickly creating simple web pages, and for standalone documents. r
  in Public bookmarks with docutils markup parser

markup from all users