it really depends on the device and the interface to it. The Generic Serial Device is a nice generic driver that supports ruby scripting. Some examples of lmce devices ("drivers") for that:
Lightning (Insteon, PLCBUS, ..)
Network Cameras (Axis, D-Link, Panasonic, ..)
AV Receivers (Marantz, Yamaha, Denon, ...)
many more
of course you also need linux drivers in some situations (usb to serial adapters, ...)
best regards,
Hari