These sources chronicle the evolution of the Agent S family of computer-use agents (CUAs), detailing improvements in performance and methodology across several iterations. Agent S introduced hierarchical planning, memory, and a constrained action space to tackle complex desktop tasks, achieving a state-of-the-art (SoTA) result of 20.6% on the OSWorld benchmark. Agent S2 significantly advanced this by implementing Proactive Hierarchical Planning and a Mixture-of-Grounding strategy, pushing the SoTA to 48.8%. Finally, Agent S3 incorporated a native coding agent and a wide-scaling framework called Behavior Best-of-N (bBoN), which generates multiple rollouts and uses concise "behavior narratives" for principled traje ...