Makepad's Relax runs Rust during compilation and patches live edits

Makepad's Relax compiler runs Rust programs while compiling functions as they are called and can patch changed function bodies into a running process without losing state, the project says. It reports reaching the first frame of a large 3D game in 11 seconds on an M4 MacBook, compared with a roughly three-minute conventional build before startup. Relax replaces rustc, LLVM and the linker during development. Its code takes 1.12 times as long on x64 and 1.24 times as long on arm64 across 21 workloads compared with stock release builds. Some crates remain unsupported, and structural edits require restarting; the project recommends rustc for release builds.