DeepSeek

DeepSeek is a Chinese AI lab whose models compete on reasoning and coding while being published as open weights. The second half is the part that matters structurally: most labs at this capability level ship an API and nothing else, so anyone with a compliance constraint or a private-deployment requirement is locked out. Open weights remove that gate. In practice DeepSeek is worth reaching for on problems where you want the chain of reasoning visible, and worth knowing about as the fallback when a workload cannot leave your own infrastructure.