This is a rewrite of the built-in SharePoint Wiki control that provides support for the Markdown formatting syntax.
SharePoint has long has Wiki support, however it's WYSIWYG editor leaves something to be desired. Frankly, it sucks. Selecting text and adding bold or trying to set an common font to entire page results in a mess of markup that echoes back to when Microsoft Word would produce the craptacular HTML output it did.
Markdown is a simple formatting syntax. It uses plain-text for formatting, is widely supported and standardized almost everywhere (everywhere except SharePoint), and is simple to use and understand and doesn't need a lot of training to learn it.
You can view a primer on the Markdown basics here.
This project is a complete replacement for the Wiki editor and is not a supplement to existing systems. Your content will be stored in Markdown format and rendered as clean HTML viewable in any browser.