We're investigating porting a fat-client .NET application to be an HTML5-based webapp, but a hangup is that we interface with a variety of usb/serial/shared devices (receipt printers, report printers, specialty archive printers, sigpads, scanners, webcams, etc).
Is there any feasible way to get an HTML5 site the ability to interface with local USB/serial peripherals, or with a local service (e.g., browse to www.site.com/app and have it interact with localhost:1234/api to request things like signatures and send stuff like print jobs)?
The other option I was thinking of is to have a local thin-client type setup, which requests UI elements from the remote server's API, but internally has logic to know what peripherals are doing and passes data via the API.
The least preferential item is to try to write some sort of browser plugin, which is is tied with using a java applet. Silverlight might work, but I haven't researched it too much.
Ideally we'd like to do this to make our app cross-platform, and we're not sure what the best practices are for our situation, or what is the path of least resistance, etc.