Whisker is a research control system developed within the University of Cambridge, UK, and marketed by Campden Instruments Ltd (UK) and the Lafayette Instrument Company (USA). It is implemented as a server that controls a range of physical devices (including digital switches for input and output devices such as levers and pellet dispensers, multiple monitors, sound cards, and touchscreens). The server communicates with clients via a TCP/IP network link and manages resources for them. Typically, individual clients are programs that implement tasks used in behavioural research (e.g. psychology and neuroscience), such as tasks involving operant chambers.