Open Source Swift Text Editors

MarkEdit is a free and open-source Markdown editor, for macOS. It's just like TextEdit on Mac but dedicated to Markdown.

Performant plain text editor for iOS with syntax highlighting, line numbers, invisible characters and much more. Runestone uses GitHub's Tree-sitter to parse code to a syntax tree which is used for features that require an understanding of the code in the editor, for example syntax highlighting. Highlight ranges in the text view. Search the text using regular expressions. Automatically detects if a file is using spaces or tabs for indentation. Specify line endings (CR, LF, CRLF) to use when inserting a line break. Automatically detect line endings in a text. When judging the performance of Runestone, it is key to build your app in the release configuration. The optimizations applied by the compiler when using the release configuration becomes very apparent when opening large documents. The project should mostly work with Catalyst on the Mac, however, it isn't fully tested and the implementation isn't considered done. The focus is currently on the iPhone and iPad.

Pine is a lightweight macOS markdown editor. It's currently a work in progress. It is a document-based application and aims to follow Apple's Human Interface Guidelines. Pine supports multiple folders and files in its sidebar. Individual files can also be opened in tabs and in separate windows. Touch Bar shortcuts are supported on compatible Macs. A Toolbar can be enabled in preferences. Markdown shortcuts are also available as keyboard combinations.

A simple Markdown editor. Notepad gives your users the ability to write and edit Markdown directly in your app. With a JSON stylesheet, it's fully themeable. Add it to your app with only a few lines of code`. Notepad is fully hackable and open-source.

TRex is the easiest way to copy uncopyable text from images, YouTube videos, Zoom calls, and more. If you can see it - you can copy it. TRex lives in your menu bar, you can initiate text capture by clicking on TRex icon or using a configurable shortcut. Your mouse cursor is transformed to a handy selection tool; use it to select an area on your screen. This could be anything - image, pdf, video - if it has text, TRex will immediately put it in your clipboard. TRex puts extracted text right into the clipboard. Just like that, you can copy anything you see on your screen. For advanced users, TRex offers automation hooks. You can launch a Shortcut or URL scheme with captured text as an input. You can help TRex better understand the text by providing a list of custom words specific to your field.

ScreenTranslate lets you translate any text on your Mac screen without switching tabs or copy-pasting. Screen Capture Translation: Press Cmd+Shift+T, drag over any text on screen, and get an instant translation popup. Works with images, PDFs, and subtitles using OCR (Apple Vision). Text Selection Translation: Select text in any app and press Cmd+Option+Z to translate directly. No OCR needed. - Free and open-source (GPL-3.0) - On-device translation using Apple Translation - Works offline with downloaded language packs - 20 languages with auto-detect - Optional cloud engines (DeepL, Google, Azure) with your own API key - Auto-copy to clipboard - Translation history with search - Lightweight menu bar app - Apple Silicon and Intel Mac supported - macOS 15 (Sequoia) or later required

Ink is a fast and flexible Markdown parsing library written in Swift that is designed to convert Markdown content into structured representations suitable for rendering or further processing. Originally developed as part of the Publish ecosystem, it focuses on performance and extensibility while maintaining a relatively simple and understandable internal architecture. The parser operates by reading Markdown input through a structured reader system that processes fragments and determines how each section should be interpreted. It uses error handling as part of its control flow, allowing the parser to efficiently decide whether to advance or rewind when processing different Markdown constructs. Ink is intended to be both production-ready and developer-friendly, encouraging users to explore and extend its functionality as needed.

MiaoYan is a lightweight, native Markdown note-taking app for macOS, built to give programmers and writers a fast, distraction-free environment for text. It is fully local-first, meaning your notes live as plain Markdown files on your machine rather than in a proprietary cloud, which appeals to privacy-conscious users. The app focuses on a minimalist three-column layout (folders, note list, editor) with syntax highlighting, dark mode, and typography tuned for Chinese and English writing. Beyond basic editing, MiaoYan supports presentation and PPT-style modes, letting you turn Markdown documents into slide-like views directly inside the app. It also adds power-user features like automatic document typesetting, internal links, LaTeX math, Mermaid and PlantUML diagrams, and Markmap mind-map rendering. Under the hood, it is implemented in Swift as a native macOS application, which keeps it snappy and lighter than Electron-based note apps.

iOS Text View (UIView) that Properly Displays LaTeX, HTML, Markdown, and YouTube/Vimeo links. In order for the RichTextView to handle the various use cases it might encounter, the input string needs to be formatted.