From Seo Wiki - Search Engine Optimization and Programming Languages
|This article needs references that appear in reliable third-party publications. Primary sources or sources affiliated with the subject are generally not sufficient for a Wikipedia article. Please add more appropriate citations from reliable sources. (February 2009)|
Markdown is a lightweight markup language, originally created by John Gruber and Aaron Swartz to help maximum readability and "publishability" of both its input and output forms. The language takes many cues from existing conventions for marking up plain text in email. Markdown converts its marked-up text input to valid, well-formed XHTML and replaces left-pointing angle brackets ('<') and ampersands with their corresponding character entity references. Markdown was originally implemented in Perl by Gruber, but has since been re-implemented by others in a variety of programming languages. It is distributed under a BSD-style license and is included with, or available as a plugin for, several content-management systems.
This is not an exhaustive listing of Markdown's syntax, and in many cases multiple styles of syntax are available to accomplish a particular effect. See the full Markdown syntax for more information. Characters which are ordinarily interpreted by Markdown as formatting commands will instead be interpreted literally if preceded by a backslash; for example, the sequence '\*' would output an asterisk rather than beginning a span of emphasized text. Markdown also does not transform any text within a "raw" block-level XHTML element; thus it is possible to include sections of XHTML within a Markdown source document by wrapping them in block-level XHTML tags.
A paragraph is one or more consecutive lines of text separated by one or more blank lines. Normal paragraphs should not be indented with spaces or tabs:
This is a paragraph. It has two sentences. This is another paragraph. It also has two sentences.
Line breaks inserted in the text are removed from the final result: the web browser is in charge of breaking the lines depending of the available space. To force a line break, insert two spaces at the end of the line.
*emphasis* (e.g., italics)
**strong emphasis** (e.g., boldface)
* An item in a bulleted (unordered) list * Another item in a bulleted list
· An item in an enumerated (ordered) list · Another item in an enumerated list
HTML headings are produced by placing a number of hashes before the header text corresponding to the level of heading desired (HTML offers six levels of headings), like so:
# First-level heading
#### Fourth-level heading
The first two heading levels also have an alternate syntax:
First-level heading ===================
Second-level heading --------------------
> This text will be enclosed in an HTML blockquote element.
[link text here](link.address.here "link title here")
![Alt text here](Image URL here "Image title here")
Horizontal rules are created by placing three or more hyphens, asterisks, or underscores on a line by themselves. You may use spaces between the hyphens or asterisks. Each of the following lines will produce a horizontal rule:
* * * *** ***** - - - ---------------------------------------
- ↑ "MarsEdit 2.3 ties the knot with Tumblr support - Ars Technica". http://arstechnica.com/apple/news/2009/03/marsedit-23-ties-the-knot-with-tumblr-support.ars. Retrieved 2009-08-11.
- ↑ "Review: Practical Django Projects - Ars Technica". http://arstechnica.com/open-source/news/2008/07/review-practical-django-projects.ars. Retrieved 2009-08-11.
- Official Markdown project at Daring Fireball
- Markdown Wiki
- Older Markdown Wiki
- PHP Markdown
- Markdownr.com, a simple website to preview markdown in real timede:Markdown