Mojo🔥 is now open source

Mojo's open-source release lets developers inspect, modify and build the compiler that translates the language into executable programs. The August 18 announcement covers the compiler and toolchain under Apache 2.0 with LLVM exceptions, following earlier releases of the standard library and kernel code. Mojo targets GPUs and other advanced processors. Primary announcement

Source availability and accepting contributions were separate decisions at launch. Developers could build their own compiler, while the maintainers said they were not yet ready to accept compiler or tooling contributions and aimed to start by the end of 2026. The standard library already accepted outside contributions.