JACK Audio Connection Kit 2/jack2
http://jackaudio.org/
There already is jack1 in the repository but jack2 have a number of features that makes it useful. For example there is support for DBUS so pulseaudio and jack can be active at the same time and it just works.
It's Open Source.
Users using JACK (audio production for example) would find this useful.
https://github.com/jackaudio/jack2/archive/v1.9.10.tar.gz
I have it packaged and could submit a patch.