Quoting Lee Revell <rlrevell(a)joe-job.com>om>: As far as I know, Audacity uses portaudio for routing audio to/from audacity. This means that Audacity will automatically support JACK if it's compiled against a proper version of portaudio. The problem is that the current stable release V18.1 doesn't support JACK. So you need to get the V19 development version. So yes, Audacity doesn't support JACK. :) .. But it does use JACK as long as you have built it againsta a newer-than-stable version of portaudio. Sampo