World Labs builds "Large World Models" (LWMs) — foundational AI systems that generate, understand, and navigate persistent, interactive 3D environments. Founded in 2023 by Stanford AI professor Fei-Fei Li (co-creator of ImageNet) alongside researchers Ben Mildenhall, Justin Johnson, and Christoph Lassner, the company's thesis is that spatial intelligence — the ability to reason and act in 3D space — is the next major AI capability gap. Their flagship product, Marble, accepts text prompts, photos, video clips, or rough layouts and outputs navigable, editable, physically coherent 3D worlds. Customers include game developers (environment generation), filmmakers (virtual sets), architects (design walkthroughs), and robotics companies using the simulated worlds as training environments. A public World API lets third-party developers embed world-modeling capabilities into their own pipelines. The July 2026 acquisition of robotics startup SceniX signals a deliberate push into physical/embodied AI — where simulated 3D worlds become the proving ground for real robots.