System Monitor 4+

System Monitor is an application for the menu bar of your Mac, designed to inform you unobtrusively about the activity of your computer. You can retrieve up-to-date technical data any time, like process load, main memory consumption, storage space, disk activity, communication on network interfaces, etc. By positioning the app in the menu bar, as least screen real estate as possible will be wasted. The program monitors your system continuously and is readily available when you need it.

If desired, System Monitor can also simulate the flickering activity lights of hard drives or network sockets in the menu bar. This is possible either in color or —perfectly integrated into the design of the operating system— in inconspicuous black-and-white. PC switchers who miss this feature on Macintosh computers can easily retrofit this function with System Monitor.