Open-source alternatives to Streamdown

Cherry Markdown is a web-based Markdown editor and parsing engine that converts markup text into sanitized HTML with a real-time synchronized preview pane. It functions as a rich text interface and WYSIWYG tool, providing a system for transforming markup strings into HTML documents or portable formats. The project distinguishes itself through high-performance rendering and a flexible extensibility model. It uses virtual DOM diffing and partial rendering to maintain responsiveness in large documents, and it allows for the creation of custom parsing rules and specialized HTML components via a p

Nextra is a documentation framework for Next.js that functions as an MDX static site generator. It enables the creation of structured technical documentation sites by transforming MDX files into themed static pages with built-in layout and navigation. It serves as a React-based documentation tool that allows the integration of custom React components directly into markdown content. The framework distinguishes itself through integrated full-text search and a localization system that manages multilingual content via language routing and translation selectors. It also includes an AI-powered chat

The minimal amount of CSS to replicate the GitHub Markdown style

js-xss is an HTML XSS sanitizer and whitelist-based HTML filter designed to remove malicious code from untrusted HTML. It serves as a tool for cross-site scripting prevention and user-generated content management by cleaning HTML strings to ensure safe browser rendering. The library includes a CSS style validator to scrub inline styles against a whitelist and an HTML content purifier capable of stripping all tags to extract raw text. It allows for custom HTML filtering through the definition of specific rules and handler functions to control permitted elements and attributes. The tool covers

This project is a Markdown static site generator and documentation server that converts files and folder structures into responsive websites. It functions as a Confluence documentation publisher, enabling the direct upload and synchronization of processed Markdown content to enterprise knowledge base servers. The system distinguishes itself through its technical rendering capabilities, transforming Mermaid syntax into visual diagrams and TeX expressions into mathematical formulas. It supports multilingual documentation by creating localized versions of a site with dedicated navigation structu

Remarkable is an extensible Markdown parser library that implements the CommonMark specification and supports GitHub Flavored Markdown through configurable rule presets. Its core architecture separates parsing into distinct inline and block rule pipelines, enabling targeted customization of text-level and structural syntax while maintaining consistent behavior across standard Markdown features. The parser is built around a plugin-based rule system where individual syntax rules can be toggled, extended, or replaced by external plugins. A preset configuration system allows users to switch betwe

Simditor is a JavaScript-based rich text editor and WYSIWYG HTML editor designed for creating structured documents within web applications. It functions as a web-based media editor and HTML content sanitizer, allowing users to compose and format content visually. The project distinguishes itself through an integrated system for handling media and security. It features server-side image upload capabilities that support both local file selection and clipboard pasting, alongside a whitelist-based HTML markup filtering system to ensure consistent and secure output. The editor provides broad capa

Dillinger is a browser-based Markdown HTML5 editor designed for real-time text editing and visual rendering. It functions as a cloud-synced writing tool that transforms markup syntax into live HTML previews, utilizing OAuth-integrated authentication to connect users with third-party services. The project distinguishes itself by integrating cloud document synchronization with external storage providers and offering direct publishing capabilities to platforms such as Medium. It also includes a dedicated Markdown-to-PDF converter for generating professional documents and a focus mode to create a

bootstrap-wysihtml5 is a rich text editor that integrates with the Bootstrap CSS framework to provide a visual interface for formatting HTML content. It functions as a localizable web editor and an HTML content parser that filters and validates tags and attributes to ensure clean content output. The project features a customizable rich text interface that allows for the modification of the toolbar and overall visual presentation through external stylesheets and HTML templates. It includes support for custom locale definitions and translated interface labels to accommodate international users.

This project is a responsive Jekyll static site theme designed for technical blogs, documentation, and multilingual websites. It focuses on text readability and the presentation of technical content, providing a customizable CSS theme with multiple color palettes and dark mode toggling. The theme distinguishes itself through specialized rendering for technical assets, including mathematical formulas, diagrams, and syntax-highlighted code. It includes built-in internationalization support via translation keys to facilitate the creation of sites in multiple languages. The capability surface co

This is an HTML sanitization library designed to remove dangerous tags and attributes from user-submitted HTML to prevent cross-site scripting attacks. It functions as a content filter that whitelists specific elements and attributes while escaping or discarding unauthorized markup. The project includes an HTML transformation engine that allows for the modification or replacement of tags and attributes using custom logic. It also features a CSS style validator to clean inline properties against permitted patterns and a system for resource URL validation to restrict hostnames and schemes. The

Hexo Theme Butterfly is a visual template for Hexo that transforms Markdown content into a responsive website featuring card-based layouts. It functions as a technical content renderer capable of displaying complex data such as mathematical formulas, Mermaid diagrams, and interactive charts within blog posts. The interface is PWA enabled, utilizing service workers and manifest files to provide offline access and installation on mobile devices. The theme distinguishes itself through a wide array of specialized content rendering tools, including musical score rendering, chronological timelines,

Vetur is a Visual Studio Code extension that provides comprehensive language support for Vue single-file components. It parses .vue files into separate template, script, and style regions, then delegates each region to its own language service for independent processing. This architecture enables IntelliSense, type-checking, formatting, and linting across all embedded languages within a Vue file. The extension distinguishes itself through deep integration with Vue's component model. It infers TypeScript types for template expressions by analyzing component props, data, and computed properti

Opentui is a terminal user interface framework for building interactive command line applications. It provides a component-based system featuring a flexbox layout engine, a virtual node component tree, and a low-level 2D cell array renderer. The project is distinguished by a sophisticated keyboard binding engine that maps complex multi-stroke sequences and chords to named commands using prioritized, reactive layers. It also implements a plugin architecture that allows external modules to inject custom UI components into designated layout slots and extend input logic at runtime. Its capabilit

yn is a markdown text editor and knowledge management tool designed as an interactive document canvas. It functions as a networked note-taking system for organizing information via wiki-links, hashtags, and local file repositories, while integrating an AI writing assistant for automated text generation and completion. The project is distinguished by its multi-engine diagramming capabilities, which render text-based syntax into visuals using Mermaid, PlantUML, and ECharts. It employs an extensible plugin framework that allows for the addition of custom UI elements and features through JavaScri

:ocean: 一款 Material Design 风格的 Hexo 主题 / An elegant Material-Design theme for Hexo

Yoopta-Editor is a headless framework for building customizable block-based rich text editors. It utilizes a JSON-based document engine to manage editor state and provides a WYSIWYG interface for creating structured documents. The system separates core document logic from the visual layer, allowing for complete customization of the user interface. The framework is designed for real-time collaborative editing, featuring a synchronization engine with conflict resolution and remote cursor presence tracking. It offers a highly extensible plugin system that allows developers to define new content

Enchanted is a privacy-focused, cross-platform chat frontend for interacting with self-hosted large language models on iOS and macOS. It serves as a native client for communicating with private model servers, specifically providing integration for the Ollama API. The application supports multimodal interactions, allowing users to combine text, image attachments, and voice prompts. It provides tools for local AI model management, including the ability to define persistent system prompts and switch between different models for specific tasks. The interface includes capabilities for rendering m

Unified is a syntax tree processing engine and content ecosystem designed to parse, transform, and serialize text content. It functions as a plugin-based content pipeline that converts raw text into structured abstract syntax trees using plain JavaScript objects for programmatic inspection and modification. The project distinguishes itself through a modular architecture that enables cross-ecosystem translation, allowing syntax trees to be converted between different specifications such as HTML and Markdown. It utilizes a system of immutable processor cloning and shared state containers, ensur

Markdig is a high-performance Markdown processor for .NET applications that converts Markdown text into HTML or other target formats. It is a CommonMark compliant parser and extensible engine that can transform Markdown into a searchable and manipulatable abstract syntax tree. The library provides a framework for adding custom syntax and rendering logic through a modular pipeline of parsers and renderers. It supports native ahead-of-time compilation and trimming to minimize binary size. Capabilities include the generation of structured HTML with custom attributes and styling, the extraction

Mindoc is a self-hosted documentation portal and API documentation management system built as a Golang web application. It serves as a markdown documentation engine for authoring, organizing, and sharing technical interface documentation and database dictionaries. The system persists project data and user accounts using MySQL or SQLite databases. The platform distinguishes itself by integrating diagrams-as-code rendering via Mermaid syntax, allowing flowcharts, sequence diagrams, and Gantt charts to be generated directly from text. It supports a flexible content pipeline that combines markdow

Markdig is a markdown parser library that converts text into structured HTML, plain text, or other formats using a configurable pipeline. It functions as a CommonMark compliant parser and an abstract syntax tree generator that transforms markdown into a hierarchical tree of block and inline nodes with precise source location mapping. The project is distinguished by a decoupled renderer architecture that separates parsing logic from output generation, enabling the transformation of the syntax tree into non-HTML formats such as LaTeX or XAML. It also serves as a lossless markdown processor by t

KaTeX is a typesetting library and web math renderer that transforms TeX and LaTeX mathematical notation into high-quality HTML and CSS for web browsers. It functions as a math notation parser and LaTeX to HTML converter, capable of operating as both a client-side library and a server-side math renderer to generate static HTML expressions. The project supports a wide range of specialized mathematical rendering, including chemical equation rendering, Bra-ket notation for quantum mechanics, and mathematical logic typesetting. It provides comprehensive controls for structural layouts such as mat

QOwnNotes is a desktop note editor that stores each note as a plain-text Markdown file on the local filesystem, avoiding proprietary formats and enabling direct file access. It functions as a Nextcloud Notes client, syncing notes and metadata with Nextcloud or ownCloud servers through a companion API service for versioning and sharing. The application also integrates with AI providers and exposes a local MCP server for external agents to search and fetch notes, and includes a companion browser extension for capturing web content, bookmarks, and screenshots. The editor distinguishes itself thr

Skeleton is a lightweight responsive CSS boilerplate and mobile-first framework. It provides a foundation for building mobile-friendly websites through a fluid 12-column grid system, a minimal CSS reset library to normalize browser defaults, and default styling for raw HTML elements. The project emphasizes a mobile-first development approach, using percentage-based widths and predefined media queries to progressively enhance layouts for larger screens. It includes a utility-first library of single-purpose classes to manage common layout tasks such as floating elements, clearing, and width con

A responsive Material Design theme for static blogs built with the Hexo framework. It functions as a comprehensive layout system that transforms markdown files into styled HTML pages, providing a specialized environment for technical documentation and personal blogging. The theme is characterized by a data-driven approach to content visualization, using radar charts for categories and word clouds for tags to represent post metadata. It further distinguishes its organization by utilizing a chronological timeline architecture for blog archives. The project covers a wide range of technical publ

TagSpaces is an offline-first file tagging and organization platform that lets you manage local files with portable metadata stored directly in filenames or sidecar JSON files, eliminating the need for a central database. It functions as a full-text file search engine, a Kanban board file organizer, a local AI file assistant, an S3-compatible cloud file manager, and a web clipper and bookmark manager, all within a single application. The project distinguishes itself through a local-first architecture where all file operations, indexing, and AI processing run entirely on the device, with cloud