Hi This is of course very close to the problems we had with firewire devices: there were published standards but they weren't always used. The difference here was that some vendors *did* adopt the standard which made things a bit easier. Even so, most still utilised vendor-specific extensions (especially for device control). AFAIK FFADO got started through the cooperation of one or two vendors and as momentum has built additional vendors have come on board to a greater or lesser extent. I expect something similar will have to happen for professional USB2 audio devices to be generally supported under Linux. Of course the other way around the problem is to do protocol analysis, but this really is the "last resort". However, in many ways this is harder on USB because as I understand it you can't have two USB bus hosts (ie: two PCs) connected to the same bus. You can probably do it using virtualisation so long as the virtualiser supports USB passthrough. The kernel's usbmon facility may then give access to the traffic as it flows. For this to work you'll need a pretty fast PC since you'll be running audio applications under a virtualised environment - I'm not sure the required timing can be met even on today's fastest hardware. In any case, there will be a lot of work involved in getting a start on this if vendor documentation is not forthcoming. I should add that from my point of view, drivers written without vendor support are really to assist those moving to Linux from other platforms who already have considerable investment in interfaces which they cannot or will not replace just to switch platforms. If considering the purchase of an interface specifically for use under Linux I would encourage you to purchase from a vendor who actively supports Linux - thereby giving them a reason to keep doing so. Regards jonathan