USB is a standard for communication between host computers and computer peripherals. The advantage of USB over other kinds of connection between a computer and a peripheral is its flexibility. USB supports plugging and unplugging of devices without need to turn off any of the components. The data flow model is designed to accommodate together peripherals with different transfer characteristics.
Adding support for USB devices to HelenOS shall improve the usability of the system in general even if the support concerns only USB 1.1 and the only peripheral drivers are for keyboards and mice.
This reference documentation can be found also on-line at homepage of HelenOS USB project at http://helenos-usb.sourceforge.net/