JACK is a low-latency audio server, written for any operating system
that is reasonably POSIX compliant. It currently exists for Linux, OS
X, Solaris, FreeBSD and Windows. It can connect several client
applications to an audio device, and allow them to share audio with
each other. Clients can run as separate processes like normal
applications, or within the JACK server as "plugins".

JACK was designed from the ground up for professional audio work, and
its design focuses on two key areas: synchronous execution of all
clients, and low latency operation.