#Carla is a plugin host. It works with both Jack and native audio setup in Linux / Win / Mac. It features a rack for linearly connecting plugins as well as a patchbay. It can run LV2s VSTs, soundfonts (sf2 and sfz), etc, etc
In addition to being standalone software, You can run Carla also as a plugin in another daw like #LMMS
I use Carla as a patchbay and to use plugins and soundfonts on a live playing and practice.
(the screenshot also features #ZynAddSubFx - a feature-rich opensource synth)