aRts

Stefan Westerfeld started aRts, the analog real-time synthesizer, as a modular synth in which oscillators, filters and effects were wired together graphically in artsbuilder, a little like a Moog in software. So that modules could live in different processes he wrote his own object system, MCOP, after CORBA had proved too slow for real-time audio, the same conclusion KDE reached with DCOP. When KDE 2.0 arrived in 2000 the desktop needed a sound server for the same reason GNOME had ESD: the sound card took one opener at a time. aRts got the job, the artsd daemon mixed every program, artsdsp caught the ones that did not know about it, and the Noatun player was built on top.

What made aRts a running joke was daily life: latency, a daemon eating CPU while nothing played, and one that fell asleep after a moment's silence and released the card, so the next sound vanished. Westerfeld announced as early as 2004 that he would not continue, and KDE 3 lived with it for four more years. KDE 4 (2008) replaced it with Phonon, which does no mixing at all but hands over to xine, GStreamer or PulseAudio underneath. The synthesizer idea survived nowhere; it was the sound server everyone remembered, and not fondly.