Owners of MultiMarkdown Composer can use the following non-sandboxed versions if needed. Most users should not need these.
MultiMarkdown Composer 2.0 (build 2) — This is the non-sandboxed version of MultiMarkdown Composer. You must have a working version of the App Store version for this to run. The 2.0 version of Composer will also respect the App Store license from Composer version 1.1.2. This means that you get free use of version 2.0 if you have purchased Composer version 1 from the Mac App Store. Future updates will require the purchase of Composer 2 from the Mac App Store. More information is here. (Updated 1/16/13)
MultiMarkdown QuickLook Generator 1.3 — A free program from Fletcher T. Penney to preview MultiMarkdown text or OPML documents as rendered web pages. An old version of this program is available on github, but this newer version is more reliable. It uses proprietary code, so the source code is not available. Requires OS X 10.7+, and 64-bit processor. More information is here. (Updated 9/15/13)
mmdc - for Composer version 2 — A command line utility that allows you to type mmdc or mmdc foo.txt to edit or create files with Composer from Terminal. (Updated 2013–01–24)
mmdc - for Composer version 1 — Installer for mmdc that works with MultiMarkdown Composer version 1.