The following message is a courtesy copy of an article
that has been posted to gmane.linux.audio.users as well.
N> But as it is, i'm thinking up a system where people can just plug
N> in their computers (ideally independent of manufacturer and OS)
N> ... admittedly not an easy task ...
Behringer X32 provides 32 i/o through a usb cable right away on linux.
While considering the 'people just plug in' part you might want to check
solutions resembling those used at CCRMA:
https://ccrma.stanford.edu/~nando/publications/openmixer_lac2010.pdf
-anders