Mojo, a programming language developed by Modular, has been released as open source under the Apache 2.0 license with LLVM exceptions. The release includes the compiler, tooling, and related code in the company's GitHub repository. The language reached version 1.0 with source stability last week.

The Apache 2.0 license is a permissive license commonly used for programming languages and compilers, offering flexibility for various applications and allowing distribution of binaries compiled with LLVM extensions. Modular described its development process as involving small design teams and community feedback to guide language evolution.

The source code for the Mojo compiler and associated tools is now publicly available at github.com/modular/modular. To build the compiler from source, users can run "./bazelw run --config=build-mojo KGEN:mojo -- run hello.mojo". An alternative using "--config=prebuilt-mojo" downloads a prebuilt binary distribution, which remains required for customizing MAX kernels or models. Contributions to the standard library have been accepted since 2024; the company plans to accept contributions to the compiler and tooling by the end of the year, though no details have been released yet. Users can ask questions or share projects through the Mojo forum.

The open‑source release aims to broaden adoption of Mojo across diverse applications, and the project will continue to open its processes as the language matures.