Overview

JACK Audio Connection Kit (JACK) is a professional-grade sound server daemon that provides real-time, low-latency audio and MIDI routing between applications. Created by Paul Davis (also the lead developer of Ardour), JACK has been the standard for professional Linux audio for over two decades. It enables sample-accurate synchronisation and flexible any-to-any signal routing that consumer audio systems cannot provide.

Key Features

• Real-Time Operation: Low-latency audio processing with deterministic scheduling for professional applications
• Flexible Routing: Connect any JACK-enabled application to any other using a virtual patch bay
• Sample-Accurate Sync: All clients run on the same audio clock for perfect synchronisation
• Network Audio: Transmit and receive audio over IP networks via netJACK and JACKTrip
• Transport Control: Centralised transport for start/stop/position sync across all clients
• Hardware Agnostic: Works with any ALSA-supported audio interface, from built-in sound cards to professional multi-channel interfaces
• Extensive Ecosystem: Hundreds of applications and tools support JACK, including Ardour, Carla, and Hydrogen

Why Use It

JACK is essential for any professional or semi-professional audio workflow on Linux. Its real-time capabilities and flexible routing make it possible to use Linux as a serious music production platform. While PipeWire is now the recommended modern alternative, JACK’s protocol remains the standard that all pro-audio software is tested against, and many users still prefer its dedicated, predictable performance.

Use Cases

• Live sound processing and routing
• Multi-track recording with external hardware
• Virtual instrument hosting and MIDI routing
• Networked audio between studio machines
• Connecting effects processors between applications

Platforms

Linux, macOS, Windows

Licence

GNU General Public License v2 (LGPL for libraries)

Website

jackaudio.org