"When Linux was created, it supported the common hardware of the day, including ATA hard disks, parallel ports, and RS-232 serial ports. Those devices are all fairly straightforward, especially when compared to recent hardware interfaces.
"In particular, the very popular Universal Serial Bus (USB) connection technology has a number of features that require special configuration in Linux. To further complicate matters, the methods of using USB devices have changed over time. Most notably, libusb and the USB filesystem are now the preferred means to access many USB devices, displacing the more traditional /dev/ file entries. Configuring the USB filesystem requires making adjustments to Linux's hot-plugging subsystem..."
