Modular open sources the Mojo compiler and toolchain under Apache 2.0 with LLVM exceptions

Sources: Modular blog, HN discussion
Summary: Modular states the Mojo compiler, tooling, and everything needed to build the language are now in the modular GitHub repository under Apache 2.0 with LLVM exceptions, one week after Mojo reached 1.0 with source stability. The build path is a single Bazel command, and the standard library tests run from the same tree. Contributions to the compiler and tooling are not being accepted yet, with Modular aiming to open them by the end of 2026, so this is readable and forkable source rather than an open development process. Modular was acquired by Qualcomm, with the acquisition completed 2026-07-29 per the company's own blog index.
Why it matters: Four years of closed compiler work becomes inspectable and forkable, while the development process itself stays closed until Modular opens contributions.
Follow-up: Track whether compiler contributions open by the end of 2026.