psutil is described as 'module providing an interface for retrieving information on all running processes and system utilization (CPU, memory, disks, network, users) in a portable way by using Python, implementing many functionalities offered by command line tools such as: ps, top, df' and is an app in the OS & Utilities category. There are more than 10 alternatives to psutil for a variety of platforms, including Linux, Mac, BSD, Windows and iPhone. The best alternative is htop, which is both free and Open Source. Other great apps like psutil are Glances (Free, Open Source), GNOME System Monitor (Free, Open Source), Resource Monitor (Free) and Linux Process Explorer (Free, Open Source).
Glances is a cross-platform monitoring tool which aims to present a large amount of monitoring information through a curses or Web based interface. The information dynamically adapts depending on the size of the user interface.
Resource Monitor is a system application in Microsoft Windows operating systems. It is used to view information about the use of hardware (CPU, memory, disk, and network) and software (file handles and modules) resources in real time.
libstatgrab is a library that provides cross platform access to statistics about the system on which it's run. It's written in C and presents a selection of useful interfaces which can be used to access key system statistics.