AI pair programmer by GitHub and OpenAI that provides code suggestions and completions directly in your IDE. Uses machine learning models trained on billions of lines of public code to suggest whole functions or lines as you type. Supports dozens of programming languages with context-aware suggestions that adapt to your coding style and project patterns. Features include multi-line completions, documentation generation, and test creation. Integrates seamlessly with VS Code, Visual Studio, Neovim, and JetBrains IDEs. Popular among professional developers for accelerating routine coding tasks and learning new patterns.