You could have downloaded DrawDown 1.1.1 for Mac from our software library for free. The application lies within Design & Photo Tools, more precisely Viewers & Editors. This software for Mac OS X is a product of RED When Excited.
From the developer:
DrawDown has been inspired by John Gruber's Markdown and has very similar goals. Enable a human readable plain text format to create rich output. Of course images are not like text, so the format respects the domain. Think of it like plain-text Photoshop. Free Command Line Tool Head over to SwiftStudies and download the free command line tool.
You may want to check out more Mac applications, such as Fiberworks Silver, which might be related to DrawDown.