# Lively4 > Lively4 is an explorative, self-supporting, web-based development environment. It's a browser-based collaborative development environment that runs entirely in the client using DOM elements, JavaScript, web components, and Babel's client-side source code transformation. Users can edit code, create web components, and work collaboratively in real-time through GitHub integration. Key characteristics: - Self-supporting: The environment can modify and extend itself - Browser-based: Runs entirely in Chrome/modern browsers - Collaborative: Real-time collaboration through GitHub sync - Web-native: Uses standard web technologies (HTML, CSS, JavaScript, Web Components) - Live programming: Immediate feedback and runtime modification ## Core Documentation - [README](README.md): Project overview and getting started information - [Getting Started Guide](doc/tutorial/index.md): Step-by-step tutorial for new users - [Documentation Index](doc/index.md): Main documentation hub with architecture overview - [Architecture Overview](doc/architecture/index.md): System architecture and design diagrams - [Manual](doc/manual/index.md): User manual and reference guides - [Keyboard Shortcuts](doc/manual/shortcuts.md): Complete list of keyboard shortcuts - [Conventions](doc/conventions.md): Coding and project conventions ## Development - [AI Coding Agent Instructions](.github/copilot-instructions.md): Essential patterns and conventions for AI agents working in the codebase - [Lively API Tutorial](doc/tutorial/lively.md): Core API documentation and examples - [Web Components Guide](doc/tutorial/web-components.md): Creating custom web components in Lively4 - [JavaScript Workflows](doc/workflows/javascript.md): JavaScript development patterns - [Test-Driven Development](doc/tutorial/reactive/tdd_for_aexprs.md): TDD approach using Active Expressions - [Libraries Documentation](doc/libraries.md): External libraries and dependencies ## Technical Reference - [Package Configuration](package.json): NPM package definition and dependencies - [SystemJS Configuration](src/systemjs-config.js): Module loading configuration - [Babel Plugin](src/plugin-babel.js): Client-side transpilation setup - [Issues Documentation](doc/issues.md): Known issues and troubleshooting ## Optional - [FAQ](doc/faq.md): Frequently asked questions - [Journal](doc/journal/): Development journal and progress notes - [Tools Documentation](doc/tools/): Development tools and utilities - [Literature](doc/literature/): Research papers and related work - [Workflows](doc/workflows/): Detailed workflow documentation for different file types