TreetopLights is an application that places a Christmas tree on the desktop and holiday lights on the menubar or screen edges. The desktop tree can be decorated with blinking or fading lights, ornaments, a treetop star, and perhaps some snow.

A small assortment of lights are available, and custom lights can be designed and added for both the tree and screen lights. The ambient lighting can be controlled for the appearance of a dimly or brightly lit room, and the transparency and size of the tree can be set to keep it out of the way, or set the perfect holiday mood.

The optional but festive menubar lights can blink or glow to decorate the menubar, or even go around the screen. A customizable countdown timer displaying days until Christmas and the twelve days of Christmas is also included for display on the desktop tree and dock icon.