Recurring report from Mozilla, The state of open source AI (v1.0.1, July 2026), introduced by its CTO Raffi Krikorian.

The thesis opens the first section: « The model layer has commoditized. Value accrues to the harness above it. » Inputs that have become commodities lose their pricing power, and the majority of production workloads run well below the frontier ceiling.

A harness tuned tightly to one lab's weights… degrades on anyone else's model, so the tighter the tuning, the less swappable the weights underneath. Lock-in arrives as a side effect of optimization.

**Mozilla** — éditeur du rapport , stateofopensource.ai

Capability state. On the Artificial Analysis Intelligence Index, the best closed model scores 61 (Claude Opus 5), the best open model 57 (Kimi K3), fourth overall; on the Epoch Capabilities Index the gap is six points, "about one release cycle", with overlapping confidence intervals. The frontier is sawtooth: open leads in frontend code, contests terminal agentic work, and clearly cedes ground on professional knowledge work.

The usage shift. The share of OpenRouter tokens routed to open weights rose from a negligible level to a majority by mid-2026, with the seven highest-volume models all open — but the report notes that by request count, closed providers still lead, the open lead being a token-volume lead concentrated in coding and agentic workloads.

The central finding: « Open ships easy. Open deploys hard. » 79% of developers use open models versus 71% closed, with half using both; but only 53% of open teams reach production versus 63%, and the gap widens with company size, which rules out an explanation by resources. The stack map confirms it: two cold columns across every layer, standardization and enterprise readiness.

The harness is the new frontier. « The agentic harness is another user agent » — the browser's role replayed one layer up. And the lock-in mechanism is stated precisely: a lab's harness, tuned to its own weights, degrades on everyone else's, so « the tighter the tuning, the less swappable the weights underneath. Lock-in arrives as a side effect of optimization. »

Sovereignty is framed as a right to exit, illustrated by Fable 5's nineteen-day blackout over export controls: « You can switch off a model. You cannot switch off a copy already running on a machine you hold. »

Mozilla advocates for what it measures. Scrupulous captions and a self-stated reversal watchlist make the data usable; the framing remains a thesis.