JACK Audio Connection Kit (or JACK; a recursive acronym) is a professional sound server daemon that provides real-time, low latency connections for both audio and MIDI data between applications that implement its API. JACK has been developed by a community of open source developers led by Paul Davis (who won an Open Source Award in 2004 for this work) and has been a key piece of infrastructure and the de facto standard for professional audio software on Linux since its inception in 2002.