AI-Native Operating Systems Need a Fifth Category: The Semantic OS — Why AIOS, rabbitOS, VAST AI OS, and NVIDIA Dynamo Still Don't Describe What Happens Inside the Context Window

AI-Native Operating Systems Need a Fifth Category: The Semantic OS Every major AI-native operating system in 2026 operates outside the model. NVIDIA Dynamo orchestrates GPUs. VAST AI OS manages the data lifecycle. AIOS (Rutgers University) schedules agents. rabbitOS translates intent into device actions. Warmwind OS automates GUIs. These are real systems solving real problems. But they all share one assumption: the operating system sits outside the model and manages it as a resource. This paper identifies a missing architectural category: the prompt-native semantic runtime — an operating system that runs inside the language model's context window at inference time, governing generation through document-level…