Urbi is a robotics software platform. It includes a C++/Java middleware API called UObject to interface components such as motors, cameras, and algorithms, and an innovative scripting language, urbiscript, with built-in support for parallel and event-based programming, used to write high-level behaviors and orchestrate the interactions between components. UObject components are built as shared libraries exposed as native objects within urbiscript, and either hot-plugged in a running Urbi engine, or started as a remote autonomous process communicating with the engine via the network. At any time, new urbiscript code can be sent to a running Urbi engine via a simple telnet, to introspect the state of components, modify existing code, or add new behaviors. Urbi is cross-platform and supports several robots (Gostai Jazz, Lego Mindstorms, Aldebaran Nao, Segway RMP, Spykee, Bioloid, etc.) and a simulator (Webots).