Doxygen - Generate documentation from source code
Typora - A minimal Markdown reading & writing app.
DocFX - A documentation generation tool for API reference and Markdown files!
Markdown by DaringFireball - Text-to-HTML conversion tool/syntax for web writers, by John Gruber
NDoc - NDoc generates class library documentation from .
StackEdit - Full-featured, open-source Markdown editor based on PageDown, the Markdown library used by Stack Overflow and the other Stack Exchange sites.