aRts (which stands for analog real time synthesizer) is an audio framework that is no longer under development. It is best known for previously being used in K Desktop Environment 2 and 3 to simulate an analog synthesizer.A key component of aRts is the sound server which mixes several sound streams in realtime. The sound server, called artsd (d for daemon), is also utilized as the standard sound server for K Desktop Environment 2–3.