Slate is a customizable framework that lets you build rich, intuitive editors like in Medium, Dropbox Paper or Google Docs.
TOAST UI Editor provides Markdown mode and WYSIWYG mode. The TOAST UI Editor offers Markdown mode and WYSIWYG mode, those can be switched at any time during writing content.
Kajero notebook is just a Markdown document with a script attached. Kajero is designed to make it really easy for anyone to create good-looking, responsive, interactive documents.
Markdownify is the simplest markdown editor with built in cloudinary image upload.
Bootstrap Markdown is a plugin for markdown editing. It exposes useful API that allow you to fully hook-in into the plugin.