Ladybird adopts Rust, with help from AI - Ladybird

Ladybird is adopting Rust as its C++ successor language, using AI agents to accelerate the transition. The first target was LibJS, Ladybird’s JavaScript engine, which was ported to Rust in two weeks, resulting in 25,000 lines of code. The Rust port was verified to be byte-for-byte identical to the C++ version, with no regressions in performance or test results. The Rust code intentionally mimics C++ patterns for compatibility, with plans to simplify and optimize the code in future iterations.