rule-based device node and kernel event manager

 udev is a collection of tools and a daemon to manage events received from
 the kernel and deal with them in user-space. Primarily this involves
 creating and removing device nodes in /dev when hardware is discovered or
 removed from the system.
 .
 Events are received via kernel netlink messaged and processed according to
 rules in /etc/udev/rules.d and /lib/udev/rules.d, altering the name of the
 device node, creating additional symlinks or calling other tools and programs
 including those to load kernel modules and initialise the device.