Abstract: In a network system, a client device is connected to the network via a controller that enables a user of the client device to carry out a task using one or more services available on the network. The controller (10) has a service discoverer (12) that discovers services at locations on the network (N) and a task manager (14) that controls the carrying out of tasks using services discovered by the service discoverer (12). The controller (10) also has a service publisher (13) that, as a result of the discovery of a service by the service discoverer (12) makes that service discoverable by other controllers (10) connected to the network, thereby allowing those other controllers to discover and access that service or services via that controller.