AI Programming Language Mojo Fully Open-Sources Compiler and Development Tools
Modular has fully open-sourced the Mojo compiler, development tools, and build components under the Apache 2.0 license with LLVM exceptions following the release of Mojo 1.0. This completes the language's transition to open source after four years of development. By open-sourcing its core compiler, Mojo addresses community concerns about vendor lock-in and proprietary control, positioning itself as a viable, open alternative to Nvidia's proprietary CUDA ecosystem. This move could accelerate its adoption across heterogeneous hardware platforms, including CPUs, GPUs, and TPUs. While the source code is now public on GitHub, Modular is not yet accepting external code contributions to the compiler and tools, with plans to open up contributions by the end of 2026. The Apache 2.0 license with LLVM exceptions allows developers to use Mojo in commercial projects and embed compiled code without licensing restrictions.
## BACKGROUND
Mojo was created by Chris Lattner, the co-founder of Modular and creator of LLVM, Clang, and Swift. It is designed to combine the simplicity of Python with the performance of C and Rust by leveraging Multi-Level Intermediate Representation (MLIR) to optimize code for modern AI hardware. In June 2026, Modular was acquired by Qualcomm, but the team committed to keeping Mojo open-source and vendor-neutral.