Open-weight AI narrows frontier gap; four-month edge costs five times as much

Mozilla’s State of Open Source AI finds the performance gap between closed frontier models and open-weight models has shrunk to about 4.4 months, with Moonshot AI’s Kimi K3 nearly matching Anthropic’s Fable 5 while costing ~30% of a closed model. Paying for closed frontier models buys roughly a four‑month head start at about five times the per‑task cost, worth it mainly for longer, more complex workloads or when out‑of‑the‑box compliance is essential. Open models are increasingly used for routine tasks (e.g., DoorDash using Kimi) and are proliferating on platforms like OpenRouter, but revenue remains dominated by closed models. The piece also calls for a broader, more open ecosystem to prevent concentration of power.