JACK differs from other audio servers in being designed from the ground up for professional audio work, focusing on two key areas: synchronous execution of all clients, and low latency operation.
JACK is free software; you can redistribute it and/or modify it under the terms of the GNU GPL and LGPL licenses as published by the Free Software Foundation, <http://www.gnu.org>. Most of JACK uses the GPL, as noted in the source file headers. But, the library interfaces are licensed under the LGPL, allowing proprietary programs to link with JACK and call its services. You should have received a copy of these Licenses along with the program; if not, write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.