JavaScript runtime Bun is migrating its development language from Zig to Rust using Claude

Bun creator Jarred Sumner says he is porting the Node.js-compatible runtime from Zig to Rust with Claude’s help.

The migration is nearly complete, and the test suite now passes on Linux, Windows, and macOS.

He says the move is aimed at reducing memory leaks, crashes, and other stability issues.

The next release may be the last major one built on Zig.