MultiMarkdown is Markdown dialect.

It is used in:

• Scrivener, which allows MultiMarkdown export, as well as -Markdown export

• iWriter Pro

It has its own style of frontmatter, e.g.

Title:    A Sample MultiMarkdown Document  
Author:   Fletcher T. Penney  
Date:     February 9, 2011  
Comment:  This is a comment intended to demonstrate  
          metadata that spans multiple lines, yet  
          is treated as a single value.  
CSS:      http://example.com/standard.css

… body of the document here …