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Apps List"],"sub_categories":["🆕 Newly Added Apps!"],"readme":"# READU.md\n\nA fast, lightweight Markdown reader \u0026 editor for Windows, built with **Fluent Design**.\n\n![.NET 9](https://img.shields.io/badge/.NET-9.0-purple)\n![WinUI 3](https://img.shields.io/badge/WinUI-3-blue)\n![License](https://img.shields.io/badge/License-MIT-green)\n[![GitHub Release](https://img.shields.io/github/v/release/breezy89757/READU.md)](https://github.com/breezy89757/READU.md/releases/latest)\n\n\u003cp align=\"center\"\u003e\n  \u003cimg src=\"docs/demo.gif\" alt=\"READU.md Demo\" width=\"800\"\u003e\n\u003c/p\u003e\n\n\u003e **[⬇️ Download Latest Release](https://github.com/breezy89757/READU.md/releases/latest)** — Extract \u0026 run, no installation needed.\n\n\u003e **[🛍️ Get it on Microsoft Store](https://apps.microsoft.com/store/detail/9MWGGZBBP1C1?cid=DevShareMCLPCS)**\n\n## Screenshots\n\n| Features \u0026 TOC | Mermaid Diagrams |\n|:---:|:---:|\n| ![Features](docs/01-features.png) | ![Mermaid](docs/02-mermaid.png) |\n\n| Dark Mode | Edit Mode (Split View) |\n|:---:|:---:|\n| ![Dark Mode](docs/03-dark-mode.png) | ![Edit Mode](docs/04-edit-mode.png) |\n\n## Features\n\n- **Multi-Tab** — open multiple files simultaneously, with drag-to-reorder tabs\n- **Edit Mode** — side-by-side Markdown editor + live preview (`Ctrl+E`)\n- **Instant Rendering** — powered by WebView2 (Chromium) and Markdig\n- **Syntax Highlighting** — code blocks highlighted via highlight.js\n- **Mermaid.js** — flowcharts, sequence diagrams, Gantt charts, and more\n- **Smart Mermaid Caching** — SHA256-based incremental DOM updates preserve rendered diagrams\n- **Dark Mode** — automatically follows your Windows system theme\n- **Table of Contents** — auto-generated sidebar with smooth scroll navigation\n- **Drag \u0026 Drop** — drop any `.md` file to open it instantly\n- **Hot Reload** — automatically refreshes when the file changes externally\n- **Scroll \u0026 Zoom Persistence** — per-tab scroll position and zoom level preserved across tab switches\n- **Print / PDF Export** — `Ctrl+P` to print or save as PDF\n- **Full Page Screenshot** — capture the entire rendered page as PNG (`Ctrl+Shift+S`)\n- **File Association** — double-click `.md` files to open in READU.md\n- **Lightweight** — minimal memory footprint, instant startup with pre-loaded CDN shell\n\n## Keyboard Shortcuts\n\n| Shortcut | Action |\n|---|---|\n| `Ctrl+O` | Open file (new tab) |\n| `Ctrl+W` | Close current tab |\n| `Ctrl+Tab` | Next tab |\n| `Ctrl+Shift+Tab` | Previous tab |\n| `Ctrl+E` | Toggle Edit / Read mode |\n| `Ctrl+S` | Save file (edit mode) |\n| `Ctrl+N` | New blank tab (edit mode) |\n| `Ctrl+P` | Print / Export PDF |\n| `Ctrl+Shift+S` | Full page screenshot |\n| `Ctrl+` `+` / `-` | Zoom in / out |\n| `Ctrl+0` | Reset zoom to 100% |\n| `Ctrl+Home` | Open Welcome page |\n\n## Tech Stack\n\n| Component | Technology |\n|---|---|\n| **Framework** | .NET 9 |\n| **UI** | WinUI 3 (Windows App SDK 1.6) |\n| **Markdown** | [Markdig](https://github.com/xoofx/markdig) |\n| **Rendering** | WebView2 (Chromium) |\n| **Syntax Highlighting** | highlight.js (CDN) |\n| **Diagrams** | Mermaid.js v11 (CDN) |\n| **Window Management** | WinUIEx |\n\n## Architecture \u0026 Trade-offs\n\nREADU.md is a **WinUI 3 desktop shell** that brings together several open-source libraries. Here's how the pieces fit and what trade-offs were made:\n\n**Markdown parsing** is handled entirely by [Markdig](https://github.com/xoofx/markdig) — a fast, extensible .NET Markdown processor. READU.md doesn't reimplement parsing; Markdig does the heavy lifting and does it well.\n\n**Rendering** uses a WebView2 (Chromium) control. This was a deliberate trade-off: a native text renderer would use less memory, but wouldn't support Mermaid diagrams, LaTeX math, or the full CSS styling that makes Markdown readable. WebView2 is pre-installed on Windows 10/11, so there's no extra download.\n\n**Shell page architecture** — CDN resources (highlight.js, mermaid.js, CSS) are loaded into the WebView2 once at startup. When switching tabs or updating content, only the HTML body is injected via JavaScript (`updateContent()`), avoiding full page reloads. This is what makes tab-switching and edit-mode preview fast.\n\n**Mermaid diagram caching** — each Mermaid code block is hashed (SHA256). During live preview updates, unchanged diagrams keep their rendered SVGs instead of being re-rendered — this prevents the \"flash\" you'd normally see.\n\n**What this project adds** on top of these libraries:\n- Native WinUI 3 app with system theme integration (Mica, dark/light mode)\n- Multi-tab document management with per-tab state (scroll, zoom, edit mode)\n- File watching with debounced hot-reload\n- Full-page screenshot via CDP (`Page.captureScreenshot`)\n- File association and drag-and-drop integration\n\n## Build\n\n### Prerequisites\n- .NET 9 SDK\n- Visual Studio 2022 17.12+ with **Windows application development** workload\n- Windows 10 (1903+) or Windows 11\n\n### Build \u0026 Run\n```bash\n# Clone\ngit clone https://github.com/breezy89757/READU.md.git\ncd READU.md\n\n# Build\ndotnet build src\\READU.md.csproj -p:Platform=x64\n\n# Or open READU.md.sln in Visual Studio and press F5\n```\n\n## Settings\n\nSettings are stored at `%LOCALAPPDATA%\\READU.md\\settings.json`:\n\n```json\n{\n  \"properties\": {\n    \"enable_mermaid\": { \"value\": true },\n    \"font_size\": { \"value\": 14 }\n  }\n}\n```\n\n## Contributing\n\nContributions are welcome! Please open an issue to discuss your idea before submitting a PR.\n\n## License\n\n[MIT](LICENSE)\n","project_url":"https://awesome.ecosyste.ms/api/v1/projects/github.com%2Fbreezy89757%2FREADU.md","html_url":"https://awesome.ecosyste.ms/projects/github.com%2Fbreezy89757%2FREADU.md","lists_url":"https://awesome.ecosyste.ms/api/v1/projects/github.com%2Fbreezy89757%2FREADU.md/lists"}