Build Your Own Text Editor

Kilo is a small-scale text editor implemented in C to demonstrate low-level systems programming. It provides a command line interface for modifying and saving text files directly within a terminal. The editor includes built-in string search and navigation capabilities to locate text within a file. It also applies colors to source code based on language patterns to provide syntax highlighting.

Helix is a terminal-based modal text editor designed for efficient code manipulation and navigation. It centers on a selection-first editing model, where operations are performed on active ranges rather than individual cursor positions, allowing for precise control over text and code structures. The editor distinguishes itself through deep integration with structural parsing and language intelligence. By utilizing an incremental parsing library, it builds concrete syntax trees that enable advanced features like structural code navigation, intelligent indentation, and syntax-aware text object selection. It also features a built-in client for the Language Server Protocol, providing real-time diagnostics, completion, and code analysis directly within the terminal interface. Beyond its core editing capabilities, the project offers a highly customizable environment. Users can define complex keybindings, manage multiple cursors for simultaneous edits, and apply declarative styling rules to customize the visual appearance of the interface. The editor also includes robust support for file discovery, buffer management, and interactive fuzzy-matched picking for symbols and commands. The editor includes a built-in diagnostic utility to verify the runtime environment and dependency configuration during setup.

Runestone is a web-based code editor component and rendering engine designed for browser-based text editing. It functions as a customizable interface that handles the visual representation of code, including line numbering, indentation, and line wrapping. The project features a rule-based syntax highlighting engine that applies colors to text ranges based on language grammar definitions. It also includes a regex-based text search engine that locates specific patterns and applies visual highlights to matching character offsets. The editor manages text input through automatic character pairing and provides tools for customizing aesthetics, such as fonts and colors. It maintains a system for managing page boundaries and formatting text structure to control the visual experience.

Textual is a Python TUI framework and asynchronous UI library used to build interactive text user interfaces. It provides a component-based architecture for creating cross-platform applications that run in both terminal and web browser environments. The framework distinguishes itself by utilizing a CSS-based layout engine to apply visual styles to widgets and a command palette interface for discovering and executing application functions. It also supports hosting terminal-based interfaces on the web to enable remote access via a standard browser. The toolkit covers a broad range of capabilities including asynchronous UI programming, widget-based layout composition, and terminal emulation. It includes observability tools for console debugging that allow system messages and events to be captured in a separate terminal instance.

notepad-- is a cross-platform plain text editor designed for creating and modifying unstructured text files. It functions as a lightweight productivity tool that allows users to write and save documents across Windows, Linux, and macOS. The application utilizes a buffer-based editing model to decouple file storage from the visual display. This approach enables a consistent user interface for local file management and plain text document creation regardless of the underlying operating system.

Micro is a terminal-based text editor designed for use within command-line interfaces. It provides a keyboard-centric environment for creating and modifying source code and configuration files without requiring a graphical desktop system. The editor features a modular architecture centered on a plugin-driven system and an embedded scripting engine. Users can extend core functionality, automate workflows, and customize editor behavior by writing scripts or installing external extensions through a centralized package management system. This extensibility allows for the integration of custom commands and behaviors tailored to specific project requirements. The application supports multi-cursor editing, enabling simultaneous text manipulation across multiple document locations to accelerate repetitive tasks. It also includes syntax-aware tokenization for real-time visual styling and provides an integrated terminal workflow that allows users to run shell sessions and command-line tools within split-pane views. The software is distributed as a static, self-contained binary, ensuring portability and consistent performance across different operating systems without the need for external dependencies.

xi-editor is a high-performance text editor core written in Rust. It employs a client-server architecture that separates the backend editor logic from the user interface, allowing diverse frontends to communicate with the core via a standardized protocol. The project is distinguished by its use of rope-based text buffers for efficient manipulation of large documents and a collaborative engine powered by conflict-free replicated data types to synchronize concurrent edits. It further features an extensible plugin system that integrates external binaries and third-party tools through JSON-based remote procedure calls. The system covers a wide range of capabilities, including incremental syntax highlighting, GPU-accelerated rendering, and asynchronous word wrapping. It manages complex document states through append-only revision history and provides low-level text processing utilities for grapheme boundary calculation and code point navigation. The backend handles expensive operations like text layout and edit merging in the background to ensure the primary user interface remains responsive.

gui.cs is a .NET terminal user interface toolkit and framework used to build interactive, cross-platform text-based applications. It provides a structured system for composing terminal views using a view hierarchy and a dedicated layout engine. The library distinguishes itself through a component-based widget system and a constraint-based layout engine that allows interfaces to remain responsive across different terminal window dimensions. It employs a virtual-screen buffer to minimize flickering during redraws and uses state-driven theme configurations to maintain persistent visual styles. The framework covers a broad range of interface capabilities, including keyboard input mapping, high-fidelity data visualization, and the rendering of high-volume data in tables and tree views. It also includes tools for designing guided workflows, such as multi-step wizards, and provides specialized controls for text editing and file system navigation.

Ratatui is a Rust framework and cross-platform terminal renderer used to build rich terminal user interfaces. It functions as a toolkit for creating interactive command-line displays, dashboards, and data visualizations. The library employs an immediate mode rendering approach, where the interface is redrawn every frame based on the current application state. It uses a widget-based layout system to compose complex text-based interfaces. The framework includes a rectangle-based layout engine and a backend-agnostic drawing system to decouple UI logic from specific terminal emulators. It further utilizes double-buffered output and state diffing to manage how characters are written to the screen.

CodeMirror is a browser-based code editor and extensible text editor framework. It functions as a programmable interface for rendering code and text with support for numerous programming languages, serving as a reusable component for web-based integrated development environments. The project provides a syntax highlighting engine that applies visual styles to text based on programming language rules. It includes a programming API and a CSS theming system to customize the editor's appearance and extend its functionality with custom behaviors. The framework covers capabilities for embedding text editors into web applications and developing specialized editing interfaces. These capabilities include implementing code editors that support syntax highlighting and integrating professional code editing tools into larger web-based environments.

This project provides an integration of Tree-sitter into the Neovim editor to enable structural code analysis. It serves as a framework for structural code navigation, context-aware syntax highlighting, and the management of language-specific parsers. The system distinguishes itself through a multi-language injection handler that identifies and parses embedded languages within a single document. It uses a dedicated parser manager to install, update, and remove grammar definitions and their associated query files. The tool covers several capability areas including incremental text selection, automated structural indentation, and semantic code folding. These features are driven by mapping syntax tree nodes to semantic categories using custom query definitions.

This framework provides a functional architecture for building interactive command-line applications. It utilizes a reactive runtime engine that synchronizes application state, user input, and visual output through a central event-driven message loop. By employing a unidirectional data flow pattern, the framework separates the definition of application state from the logic that processes updates and the declarative rendering process that transforms state into terminal-ready output. The framework distinguishes itself through its approach to side-effect management and terminal environment adaptation. It encapsulates asynchronous tasks as discrete commands that execute outside the main loop, allowing for non-blocking orchestration of background operations like network requests or file system access. To ensure consistent behavior across diverse environments, it includes a normalization layer that queries terminal capabilities, monitors window dimensions for responsive layouts, and handles complex input streams including mouse and keyboard events. Beyond its core runtime, the framework supports a broad range of operational requirements, including timed event scheduling, command batching, and persistent output rendering for status updates. It offers flexible initialization through functional configuration patterns and provides diagnostic utilities such as file-based logging to assist in debugging interfaces that occupy the standard output stream.

This project is a Python terminal user interface library and toolkit designed for building interactive command-line applications. It provides a terminal input manager and a widget toolkit for rendering dashboards, menus, and editors within a terminal emulator. The library enables the creation of full-screen terminal interfaces and interactive shells. It distinguishes itself with advanced input handling, including lexer-based syntax highlighting for visual feedback on code structure and support for industry-standard keyboard navigation modes such as Emacs and Vi. The capability surface covers comprehensive input handling and user interface design. This includes multi-line editing, predictive ghost-text suggestions, auto-completion, and mouse-driven cursor control. It also provides tools for incremental input search and buffer management to track multiple input states.

Monaco Editor is a web-based text editing component designed to provide advanced syntax highlighting, code completion, and language intelligence within browser environments. It functions as a reusable interface element that enables developers to integrate professional-grade coding experiences into web applications. The editor distinguishes itself through a native client for the Language Server Protocol, which connects the interface to external analysis tools for deep diagnostics and refactoring capabilities. It utilizes a memory-efficient, declarative text buffer to manage large documents and supports complex workflows such as rich text diffing for version control. To maintain responsiveness during intensive tasks, the system offloads lexical analysis to background worker threads and employs an incremental tokenization engine that re-evaluates only modified document segments. The architecture relies on a decoupled rendering model and a centralized action registry to manage user inputs and visual overlays independently of the core text state. This structure allows for extensive customization, including the implementation of domain-specific language definitions and specialized visual styling.

Btop is a terminal-based system monitor that tracks and displays real-time hardware performance metrics. It functions as a resource usage dashboard, providing visibility into processor, memory, disk, network, and active process activity directly within a text-based interface. The application utilizes ANSI escape sequences to render complex graphical interfaces and data visualizations within standard terminal emulators. It is designed as a cross-platform performance tool, maintaining consistent monitoring capabilities across various Unix-like operating systems through a platform-agnostic build abstraction. Users can manage the application's runtime behavior and visual configuration through command-line arguments or persistent local configuration files. The tool supports granular control over settings such as update rates, themes, and process filters, and includes functionality for monitoring graphics hardware performance.

This project is a terminal user interface library for Node.js, designed to facilitate the construction of interactive command-line applications. It provides a comprehensive toolkit of high-level widgets that abstract complex terminal escape codes and rendering logic, allowing developers to build functional interfaces using reusable components. The framework distinguishes itself by implementing a box-model-based layout engine and a virtual DOM-style reconciliation system. These mechanisms enable responsive design patterns—such as percentage-based sizing and relative positioning—to function within a terminal environment while minimizing screen flickering during redraw cycles. It further supports event-bubbling for keyboard and mouse interactions, ensuring consistent input handling across nested interface hierarchies. Beyond standard interface construction, the library includes capabilities for rich content display and advanced styling. It supports tag-based markup parsing for text formatting and integrates with external utilities to render images, animations, and video directly within the terminal window. These features allow for the creation of structured data displays, such as tables and logs, alongside interactive elements like hover-triggered tooltips and draggable components.

Rich is a Python terminal formatting library and user interface framework. It provides tools for rendering rich text, colors, and complex layouts within a terminal environment, including specialized formatters for markdown and source code syntax highlighting. The library distinguishes itself through high-level UI components such as tables with unicode borders, hierarchical tree views for nested data structures, and a system for building structured terminal user interfaces. It also includes a debugging visualizer for pretty-printing complex data and formatting error tracebacks. The capability surface covers data visualization via progress bars and activity spinners, as well as observability tools for object inspection and terminal log formatting. Layout management is handled through columnar content arrangement and emoji support.