I'm trying to figure out if it's possible to access a Midi device (like a piano/keyboard or electronic drum set) that is plugged into to a clients USB port over the web.
Obviously the browser security model makes this impossible using just javascript and while it looks like the emerging html5 device standard might help in the future it's apparently not there yet.
So what about flash, silverlight or java? The closest I've found is that silverlight seems to be able to do it if the app is trusted, but that's not a very easy thing to convince a user to do.
Any options?
The only practical way (that I know of) to achieve this using Silverlight, is platform invocation. This requires Silverlight 5 and the app to run in full trust mode, which makes sense because the app can do pretty much anything with P/Invoke. If a web app allows the developers to access information on a client's computer, then there will have to be some warning or user sign-off (like Silverlight's full trust).
Yes, this is possible, at least in Windows and MacOS. I'm not sure how to post a link here, but you can google for "Jazz-Plugin"
来源：https://stackoverflow.com/questions/8686577/accessing-a-usb-midi-device-via-the-web