Who Pays for Clang

The analysis maps who paid for work on Clang and LLVM from 2010-2026 by attributing commits, pull-request approvals, and the code areas touched to employers identified from commit emails and public profiles. It shows a clear shift from Apple and Google dominating early Clang development (about 84% of Clang commits in 2010, 61% in 2014) to a much more diversified funder mix by 2026, when Apple+Google account for roughly 16% of Clang commits. New and growing contributors include NVIDIA, AMD, Intel, Red Hat, Arm, Microsoft, Bloomberg, and C++-conformance sponsors; the llvm/ tree exhibits the same trend, with AMD the single largest funder of llvm/ in 2026 and Google+Apple falling from 72% to about 17%.

The substance shows not only who writes code but what they write. Vendor-paid work has become more specialized: NVIDIA, AMD, Arm, and Microsoft do 68-86% of their Clang commits on language modes or target-specific code, and overall "specific" commits rose from 23% in 2024 to 41% in 2026, driven largely by the explosion of CIR contributions. Core, cross-cutting Clang work is concentrated in fewer actors - individuals, Google, Apple, and Red Hat - and review activity is concentrated too: individuals author 30% of PRs but provide only 10% of approvals, while a small set of approvers handle a large share of reviews. The result is that vendor-specific features are primarily maintained by the vendors that need them, while a small group shoulders much of the shared maintenance and review burden.