Spy is a CPU load monitoring utility that displays the information in the menu bar. It is not an application but a collection of loaded bundles.
It displays the load by displaying two small cirlces in your menu bar. The inner circle shows the system load, the outer circle the user load. The black line length displays instantaneous load reading. Average reading, if enabled, is provided by looking at the level of transparency on the rest of the circle.
RequirementsMac OS X 10.2 or later
*Previously available here