The license choice is the story the benchmarks obscure. Previous open-weight releases that approached frontier performance arrived under non-commercial or restrictive RAIL-style terms, which let closed-source labs dismiss them as hobbyist tools unsuitable for production. DeepSeek V4 under MIT eliminates that dismissal. An enterprise deploying V4 Pro can modify weights, fine-tune for proprietary tasks, and serve inference without royalty exposure — the exact commercial flexibility that made closed-source APIs the default for serious workloads.