Are there any standards for markup like the one that SO site uses?

Question

I will like to design/develop a formatting markup for an application that we are developing. Is there any standard on this like what StackOverflow uses when writing each question description.

Answer 1

SO uses Markdown. Other interesting approaches include Wikitext and BBCode.

Answer 2

There are lots and lots of lightweight markup languages out there. Markdown and Textile are two that I like.