GKrellM is a system monitor utility that was originally designed for Linux, but which now runs on a number of operating systems including OS X, Linux, and Windows.

Out of the box, the utility includes modules for monitoring your CPU, memory, and network use as well as running processes and several other items. Each module can be customized to look different or display different information. And there's a huge list of plugins that you can use to add features like:

• Show clipboard entries
• Display images
• Show the time in several different time zones
• Monitor your Folding@Home account
• Control media players

And the list goes on.

GKrellM is an open source application, with installation packages available for Windows and several Linux distributions including Debian, SUSE, RedHat, and Mandrake. It's also available for FreeBSD, NetBSD, and OpenBSD. Getting it up and running on OS X is a bit more complicated, but still doable.

[via MakeUseOf]