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)¡±. 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). -- Wikipedia
Long story short, the world have two significant word processing tools: TeX and MS-Word, it present two completely different design philosophy.
1.The TeX is extremely to master and use, but it provide the ultimate freedom, the position of text is exactly where you want put it at.
2.The MS-Word is extremely to use, but you can do nothings about it if the text is not at the position where you want it to be after long time many times trying.
3.Markdown is between TeX and MS-Word, provide a easy to use and a limited freedom(enough) for some light weight work(Blog, Email, HTML, etc.), it is a balance of TeX and MS-Word, what's more important is writing use markdown let you ignore the text formating and think deeper.
Markdown is also a Perl script written by Gruber, Markdown.pl, which converts marked-up text input to valid, well-formed XHTML or HTML and replaces left-pointing angle brackets and ampersands with their corresponding character entity references. It can be used as a standalone script, as a plugin for Blosxom or Movable Type, or as a text filter for BBEdit. Markdown has since been re-implemented by others as a Perl module available on CPAN (Text::Markdown), and in a variety of other programming languages. It is distributed under a BSD-style license and is included with, or available as a plugin for, several content-management systems.
Heading marked with #, sub-heading plus(+) one more #. (Note: level one and level two heading can be marked with =================== and --------------------)
emphasis or emphasis, use * because it more distinguished due to symbol * used by list. stong emphasis or stong emphasis, use * same reason to above.
"Write something." The above will translate into following HTML:
Links may be included inline:
link text here Ex. Markdown
Alternatively, links can be placed in footnotes outside of the paragraph, being referenced with some sort of reference tag. For example, including the following inline:
[link text here][linkref] would produce a link if the following showed up outside of the paragraph (or at the end of the document):
[linkref]: link.address.here "link title here"
Perl script(1450 lines of code) Markdown.pl