Rust

GitHub says it used Copilot itself to help migrate the GitHub Copilot agent runtime to Rust, a rewrite spanning 800,000 lines of production code. The company frames the project as evidence that agentic coding tools now make large-scale rewrites economically viable.

GitHub used its own Copilot agent to help migrate the Copilot runtime to Rust, producing roughly 800,000 lines of production code. The company says the scale of the rewrite would not have been feasible without agentic coding assistance.