mojo-lang open-source compiler build-systems apache-2.0

Mojo compiler open sourced under Apache 2.0

Clone the Mojo compiler from GitHub, build with Bazel, modify stdlib and run tests locally—but compiler contributions are closed until end of year.

Summary

Developers can now inspect the compiler implementation, fork custom toolchains, and iterate on stdlib code without waiting for releases. Build-from-source workflows replace binary-only constraints.

Why it matters

Developers can now inspect the compiler implementation, fork custom toolchains, and iterate on stdlib code without waiting for releases. Build-from-source workflows replace binary-only constraints.

Implementation verdict

Replaces closed-source compiler with Apache 2.0 source tree. Requires Bazel, local build infrastructure, and git workflow. Ready to build and audit now; hold on compiler contributions until Q4. Worth cloning if you need vendor independence or deep language customization.

Sources

1.Mojo language is now fully open source under the Apache 2.0 license (with LLVM exceptions)
2.Last week Mojo hit 1.0 (with source stability), and today we're excited to open source the entire compiler and toolchain
3.we aren't ready to take contributions to the compiler and tooling. We aim to accept contributions to the compiler and tooling by the end of this year
4.git clone https://github.com/modular/modular.git
5../bazelw run --config=build-mojo KGEN:mojo -- run hello.mojo

Dev Signal

Get briefs like this in your inbox — free, every weekday.

100+ sources compressed into one 4-minute read. Ranked, cited, implementation-ready.

Read the full issue →All briefs