Open Source PHP Markdown Editors

BookStack is a free and open source platform for storing and organising information and documentation. A self-hosted and opinionated wiki system, BookStack is simple and easy to use, giving even new users with just basic word-processing skills a pleasant out of the box experience. BookStack offers a relaxed, open and positive approach. While the platform can provide advanced power features to those who want them, it is primarily designed not to be extensible outside of its core purpose. That being said, BookStack already comes with plenty of powerful features, such as search and linking, cross-book sorting, image management and more. It is also multi-lingual and offers options for authentication integration.

HTMLy is an open source databaseless PHP blogging platform. A flat-file CMS that allows you to create a fast, secure, and powerful website or blog in seconds. HTMLy uses a unique algorithm to find or list any content based on date, type, category, tag, or author, and it's performance remains fast even if we have tens of thousands of posts and hundreds of tags. As a flat-file CMS, HTMLy is designed to run smoothly despite using minimal server specs. With 512MB of RAM or even in shared hosting, it should handle more than 20K posts without any issues. Simple but not simpler. A lot of built-in features to supercharge your blog. Recent posts, popular posts, archive lists, category lists, tag clouds, sitemaps, menu manager, scheduled posts, and many more. Ever heard of complaints about unsafe, outdated, and slow plugins for specific CMS out there? We will not follow the same steps. Any new features will be added to the core and go through a security audit.

Grav is a modern open source flat-file CMS. Performance is not just an afterthought, we baked it in from the start. Grav has a powerful API and sophisticated Package Manager to make it super flexible. Grav is Open Source, and all the code is available on GitHub.com. The Grav admin plugin provides a simple and intuitive interface to make configuration and content creation easy and enjoyable. Packed to the gills with amazing features and tools, coupled with heaps of detailed documentation, Grav will make you look like a hero developer! Use your favorite Markdown editor to create your content online or offline. The built-in Package Manager lets you to find, install, and easily update extensions and themes for Grav. Grav intelligently caches content to deliver great performance, regardless of hosting. Create unlimited taxonomies such as tags, categories, and authors to filter and manage your content.

Library which converts HTML to Markdown for your sanity and convenience. You have an existing HTML document that needs to be edited by people with good taste. You want to store new content in HTML format but edit it as Markdown. You want to convert HTML email to plain text email. You know a guy who's been converting HTML to Markdown for years, and now he can speak Elvish. You'd quite like to be able to speak Elvish. You just really like Markdown. By default, HTML To Markdown preserves HTML tags without Markdown equivalents, like span and div. To strip HTML tags that don't have a Markdown equivalent while preserving the content inside them, set strip_tags to true.

A web-based markdown viewer optimized for Obsidian Notes. Just put your whole Obsidian vault or markdown folder/file structure in your web directory. The page builds itself. It's an open source alternative to Obsidian Publish.

cebe/markdown is a super fast, highly extensible markdown parser for PHP. It is a set of PHP classes, each representing a Markdown flavor and a command line tool for converting Markdown files to HTML files. The implementation focus is to be fast (see benchmark) and extensible. You are able to add additional language elements by directly hooking into the parser, no (possibly error-prone) post- or pre-processing is needed to extend the language. It is also well-tested to provide the best rendering results also in edge cases where other parsers fail.