When comparing MultiMarkdown Composer vs MacDown, the Slant community recommends MacDown for most people. In the question“What are the best Markdown editors for OS X?” MacDown is ranked 6th while MultiMarkdown Composer is ranked 13th. The most important reason people chose MacDown is:
MacDown is a free and open source editor influenced by [Mou](http://25.io/mou/). It's released under the MIT license.
Ranked in these QuestionsQuestion Ranking
Pro Multimarkdown Support
Not many popular markdown editors support multimarkdown syntax
Pro Table of Contents support
Generates a table of contents based on the headers in the Markdown file being worked on.
Pro Support for elastic tabstops
Elastic tabstops are used to align text automatically during writing. When there's a change in the text, MultiMarkdown Composer automatically aligns all lines both on the beginning and end of them.
Pro CriticMarkup support
Pro Optional Synchronized Scrolling
Hold a key down and get synchronized scrolling.
Pro Multiple export options
You can export to HTML, PDF, LaTeX, RTF, OpenOffice, Microsoft Word, ePub, OPML.
Pro Fast syntax highlighting
Pro Highly customizable
Pro Counts words, characters, lines
Pro Can show invisible characters
Pro Free and open source
MacDown is a free and open source editor influenced by Mou. It's released under the MIT license.
Pro Real-time split-screen preview
MacDown's main view is split into two panels. The user types on the left and the Markdown is rendered on the fly in the right panel. This helps users to better understand the way they are formatting their document.
Pro Good auto-completion
MacDown has a good built-in auto-completion engine for Markdown symbols.
Pro Markdown previews can be customized with CSS
You can use a CSS file to customize the rendered output and the file preview you are working on will display the rendered Markdown with the custom CSS styling on top.
Pro Supports syntax highlighting in fenced code blocks
MacDown has syntax highlighting support for various languages when writing code in fenced code blocks.
Pro Support for GFM
Pro Ideal for day-to-day programmers' work and MarkDown novices alike
Using MacDown for the notorious README.md use case gets you going without reading any manual or requiring any configuration values. Think of it as a sort of TextEdit for MarkDown files. Thus its shortcomings - neither powerful nor versatile - turn out to be a PRO for novices trying to jump on the MarkDown bandwagon. Open its help and you'll immediately find yourself editing the MacDown's MarkDown help file, a MarkDown primer with some MacDown menus and configuration added.
Con Table of contents gets out of sync sometimes
If you keep the auto-generated table of contents open while you work it gets out of sync, meaning items in the table of contents (at the end) disappear until you restart the program.
Con The way the preview shows images is inconsistent
The preview is a bit inconsistent with images. Sometimes it shows the image correctly, sometimes it shows a blue question mark.
Con Not very versatile
MacDown is not very powerful or versatile. It's not customizable or extendable. This is what makes it so simple, but it's not for people who want more from their tools.
Con The Markdown preview is rather heavy on the CPU
The Markdown preview needs a lot of resources to keep rendering on-the-fly after each keystroke. A single keystroke in the editor panel may trigger up to 5 seconds of max-CPU usage.