Lean is an open-source programming language and proof assistant that enables correct, maintainable, and formally verified code.


Lean is an open-source programming language and proof assistant that enables correct, maintainable, and formally verified code.


VSCoder Copilot connects your mobile device to your desktop VS Code instance, giving you real-time access to GitHub Copilot and your codebase — securely, without VPNs or open ports.



