simplemde-markdown-editor

SimpleMDE is a JavaScript text editor you can embed in any webpage to give visitors a comfortable writing experience. It is designed for Markdown, a plain-text formatting system where you type symbols like asterisks and hash marks to indicate bold, headings, and links. The editor shows those formatting choices visually as you type, so bold text actually looks bold and headings look large, rather than forcing you to click a preview button to see what you will get.

The main audience is website builders who want to add a rich writing area to a page without requiring visitors to know Markdown syntax. The editor provides a toolbar with familiar buttons, so someone who has never written a line of Markdown can still click a bold button and get bold text. Spell checking runs automatically, and an autosave feature quietly saves whatever is being typed so that work is not lost if the browser is closed.

Installing it takes a few lines of code. You can pull it in via a package manager or link to a hosted copy from a content delivery network. Once loaded, you point it at any text input box on your page and it transforms that box into the styled editor. Everything is configurable: which toolbar buttons appear, what keyboard shortcuts do, how tabs and indentation work, whether line wrapping is on, and more.

The project is archived and no longer maintained, which means it receives no updates or bug fixes. A community fork called EasyMDE continues active development and is generally recommended for new projects. For someone who just needs a working, embeddable Markdown editor and is willing to live with the existing feature set, SimpleMDE still functions as documented.