NINJAM
Internet jamming software that gives up fighting latency and instead delays everything by exactly one musical phrase.
Cockos, the company Justin Frankel started after Nullsoft, released NINJAM in 2005 under the GPL. The name stands for Novel Intervallic Network Jamming Architecture for Music. Rather than chasing milliseconds like JackTrip, the session agrees on an interval — say 16 bars at 120 BPM. Each player hears what everyone else played during the previous interval, lined up against their own.
It works surprisingly well for music built on repetition, such as blues and electronic loops, and baffles everyone the moment there's a chord change that matters. Since the delay is huge anyway, the audio can be compressed with Vorbis, so ordinary home connections cope. A client is built into REAPER.