Virtual Audio Cable - Ever wanted to record your speaker output? (loopback) This is for you.
Voicemeeter - Audio Processing and Audio Programming by V.Burel
Helvum - A GTK patchbay for pipewire.
qpwgraph - graph manager dedicated to PipeWire, using the Qt C++ framework, based and pretty much like the same of QjackCtl.
JACK Audio Connection Kit - JACK Audio Connection Kit|Home
Loopback by RogueAmoeba - Get all the power of a high-end studio mixing board, right inside your Mac!