Jalv is a simple but fully featured LV2 host for Jack which exposes plugin ports to Jack, essentially making any LV2 plugin function as a Jack application. For more information, see http://drobilla.net/software/jalv.
Jalv is a small program which is useful, but also intended to be an appropriate test host for plugin development. It runs plugins from the command line with no user interaction, is light enough to run in valgrind, and is capable of dumping all communication between the plugin and its UI in a human readable format.
To make it simple to test plugins in hosts that use different toolkits, there are several Jalv executables: jalv, jalv.gtk, jalv.gtk3, jalv.gtkmm, jalv.qt4, and jalv.qt5.
-- David Robillard d@drobilla.net