@xenogon I'm using the Digiface USB, which some hero made drivers for in the latest linux kernel.
I've had it running for a couple months, but it's not been perfectly stable, and a kernel updated created a snafu.
Fortunately, I've been able to do some kernel re-organizing and it seems to be working nicely again, so yay! Pretty cool to have 32 I/O in Linux! :)