Conventional computers provide some basic information with the help of LEDs. Modern computers often lack these LEDs or they are not in a clearly visible place. AddLEDs replaces or supplements them by means of software. AddLEDs displays the state of the Caps Lock, Num Lock and Scroll Lock keys and provides information on network and disc activity with the help of icons. Each of these information has its own tray icon ("Virtual LED") which indicates the given state in an informative way.