Does anyone have some good suggestions for medium format film (negative) usb scanners?

I'll use either a mac or linux machine, but the linux machine is more convenient. It seems the commercial program vuescan www.hamrick.com will interface with most scanners. I don't object to this but would prefer an open source interface. So, if you know of a good medium format film scanner scanner, great, since vuescan probably works with it, but if you know of one that definitely works with linux that's even better.

TIA, David