Open Sound Control (OSC) is a protocol for communication among computers, sound synthesizers, and other multimedia devices. OSC's advantages include interoperability, accuracy and flexibility allowing for multiple commands to be sent simultaneously.
OSC offers real-time control of audio and other media processing devices while remaining both flexible and easy to implement.
OSC can be sent from buttons with a fixed messages or with variable values from other control types.
Furthermore, Ctrl for iPad features an OSC API (methods located under applicable control types) which allows the theme, state, label and more to be controlled remotely.