“If you write in Markdown on the Mac, you need this.” -One Thing Well
Marked is a previewer (not an editor) for MultiMarkdown, Markdown, Text and HTML files. It watches the original file for changes, updating the preview any time the file is saved. With a full set of customization options and preview styles, Marked adds an ideal “live” Markdown preview to any text editor.
Markdown (John Gruber) is a plain-text formatting syntax that you can use anywhere you can type. Many applications are becoming aware of it, and Marked helps you make it work everywhere. Marked uses MultiMarkdown (Fletcher Penney), a superset that adds additional capabilities including metadata, tables and footnotes.
You can also use a custom processor with Marked, making it compatible with any form of Markdown or even other languages such as Textile.