MC and Max for Live
Max for Live devices receive audio input via plugin~ and send audio to Live via plugout~. The mc.plugin~ and mc.plugout~ versions of these objects accept multi-channel inputs and outputs to be routed to and from Max for Live.
Devices created with multi-channel inputs and outputs will support multichannel routing within Live, as well as having the appropriate number of inlets and outlets when loaded into Max within the amxd~ object. The current maximum channel count is 64.