The Markdown language was created in 2004 by John Gruber with substantial contributions from Aaron Swartz, with the goal of allowing people to

write using an easy-to-read, easy-to-write plain text format, and optionally convert it to structurally valid XHTML (or HTML)

Callimachus supports John Gruber's Markdown syntax.

Pragma Description
?html Responds with just the HTML markup produced by this markdown file