Download of MDEdit 1.5 for Mac was available from the developer's website when we last checked. We cannot confirm if there is a free download of this app available.
Please check the Mac app with an antivirus before launch as it is downloaded from the developer's website, and we cannot ensure that it is safe. The software lies within Developer Tools, more precisely General. This free Mac app is a product of FirmShell Ltd.
From the developer:
MDEdit is a handy editor for web developers on Mac OS X. You can write in any language, thanks to the UTF8 support. The tool lets you use custom fonts, as well as multiple built-in themes and CSS. With the auto-save mode enabled, the app saves your work automatically. The program supports multiple file extensions, such as .md, .markdown, .txt, .mkd, etc.
You may want to check out more Mac applications, such as TopCoder UML Tool, DecoderPro or Go2, which might be related to MDEdit.