Writedown 是 Sofish 开发的一款Markdown编辑软件，支持 Github flavor markdown，提供了预览和 HTML Copy 功能，具备热键：
- Preview:
command+shift+p - Back to Editor:
ESCorcommand+shift+b - View HTML Source:
command+shift+h - Copy HTML:
command+shift+c - Save:
command+s - Settings:
command+
