The same problem applies to most point of sale hardware, the stuff we use doesn't mostly care about drivers at all. Receipt printers just want raw bytes sent to their port, no matter COM or LPT or LAN - OS is bit of an obstruction on the way. Kind of sad that web-based POS software can't take full advantage of the conveniences web brings (ease of updating the program, easier and prettier graphical designs) without losing the capability of interfacing properly with hardware.