Modular has released the full source code for the Mojo programming language under the Apache 2.0 license with LLVM exceptions. The Modular GitHub repository now includes the Mojo compiler, tooling and components needed to build the language. Mojo is a general-purpose language designed to apply modern compiler and programming-language research to GPUs, AI accelerators and other advanced computing hardware. Mojo 1.0 recently reached source stability, following four years of development in which the language had an open community but a closed compiler. Modular had previously open-sourced Mojo’s standard library, kernel code, tools and support components. The Apache 2.0 license permits broad use, while the LLVM license exceptions expand permissions for building and distributing binaries compiled from Mojo. Developers can clone the Modular repository and use Bazel to build the compiler and standard library locally. The `--config=build-mojo` setting compiles the toolchain from local source, and developers can run standard-library tests through Bazel. The `--config=prebuilt-mojo` setting downloads a nightly compiler binary instead, although Modular says a prebuilt compiler remains necessary for customizing MAX kernels or models. Mojo’s standard library has accepted outside contributions since 2024, but Modular is not yet accepting contributions to the compiler or tooling and aims to do so by the end of the year.

Mojo language has officially reached version 1.0, marking its evolution into a stable, general-purpose programming language since its initial release in 2023. The 1.0 version supports a vibrant developer community in creating libraries, tools, and applications, providing a production-ready foundation for long-term development.

Mojo is a programming language designed to combine the user-friendliness of Python with the performance of C++. It allows developers to write fast code for various hardware, including CPUs and GPUs, while ensuring memory safety and avoiding vendor lock-in.