TOAST UI Editor, allows you to edit your Markdown documents using text or WYSIWYG and comes with Syntax Highlighting, Scroll-Sync, Live Preview, and Chart features:

TOAST UI Editor, allows you to edit your Markdown documents using text or WYSIWYG and comes with Syntax Highlighting, Scroll-Sync, Live Preview, and Chart features:
* https://ui.toast.com/tui-editor
* https://github.com/nhn/tui.editor