The JACK Audio Connection Kit or JACK is a daemon that provides low latency connections between so-called jackified applications. It is created by Paul Davis and others and licensed under the GPL. JACK is free audio software. It can use ALSA, PortAudio and (still experimental) OSS as its back-end. As of 2003 it runs on Linux and Mac OS X.
Some software that works with JACK:
- qjackctl  is a Qt based tool to control JACK.
- Ardour, a hard disk recorder
- SuperCollider, a realtime audio programming language
- XMMS, using xmms-jack
- Freqtweak  is a program that allows for individually tweaking the frequency bands.
- Demeter can show distortion in JACK systems and AD/DA converters
- JACK Rack
- JACK Timemachine is a simple program to record sounds that would otherwise have been lost
- LADCCA  is the Linux Audio Developer's Configuration and Connection API, a session management system for audio applications
- PyJack Python module to provide an interface to the JACK server
- k_jack adds JACK capability to pure data
- libjackasyn is a library that converts programs written for the OSS system into JACK-aware applications.