Lightning 3 Renderer

The High-Performance 2D Renderer for Lightning 3

Lightning 3 Renderer is the core rendering engine that powers Lightning 3 applications. It enables highly performant user interfaces on web browsers, with specialized support for embedded devices using WebGL and Canvas rendering.

Lightning 3 Renderer is one component of the Lightning 3 platform. When building applications, you typically use it in combination with Blits, the application framework, which provides a higher-level API for building interactive user experiences.

In Production

Lightning 3 Renderer is trusted by major broadcasters and streaming providers worldwide, eg:

• Sky Sports+ – Sky Group
• Xfinity Stream – Comcast
• Xfinity X1 Sports - Comcast
• Next-Generation Comcast/Sky Entertainment OS

This project is the result of collaboration between Sky Group, Comcast, and NBC Universal teams, building on proven technology from Lightning 2 and refined for the modern web. Used on 10M+ embedded devices worldwide from STBs to various Smart TVs.

Managed by RDK Management

Lightning 3 Renderer is managed through the RDK Management Open Source initiative, ensuring open governance and community collaboration.

Key Capabilities

• Cross-Device Support: Optimized for everything from Chrome v38 (2014) to modern browsers
• Platform Abstraction: Intelligently adapts to browser capabilities with automatic fallbacks
• Performance-First: Engineered for embedded devices and streaming applications with minimal overhead
• Multiple Rendering Modes: WebGL for modern browsers, Canvas fallback for legacy systems
• Advanced Typography: Support for both SDF and Canvas-based font rendering
• Modular Architecture: Extensible platform system for custom optimizations

Quick Start

Requirements

• Node.js >= 18.0.0
• pnpm >= 10.17.0

Install & Build

# Install dependencies
pnpm install

# Build the renderer
pnpm build

# Watch mode for development
pnpm watch

# Run tests
pnpm test

# Start example tests
pnpm start

For detailed setup instructions and development workflows, see Getting Started.

Documentation

• Getting Started – Installation, build commands, development workflow
• Platform Architecture – Understanding and selecting rendering platforms (WebGL, Canvas, legacy support)
• Font Loading – Installing and using Canvas and SDF fonts
• Browser Support – Detailed browser compatibility and feature matrix
• Example Tests – Manual testing and visual examples
• Visual Regression Testing – Automated visual regression test suite
• API Documentation – Complete API reference (generated via TypeDoc)
• Migration Guide – Upgrading from Lightning 3 v2.x

Contributing

We welcome contributions! Please see CONTRIBUTING.md for guidelines.

License

This project is licensed under the Apache License 2.0. See LICENSE and NOTICE for details.

See Browsers Supported for a comprehensive list of tested browsers and their specific capabilities, including support for older embedded device browsers.

Learn more: Visit LightningJS.io for the full Lightning 3 documentation and Blits framework guide.