iStat Menus - "An advanced Mac system monitor for your menubar."
iftop - iftop does for network usage what top(1) does for CPU usage.
MenuMeters for El Capitan - MenuMeters for OS X El Capitan 10.11 (and later)
nmon - This systems administrator, tuner, benchmark tool gives you a huge amount of important performance...
Stats - Simple macOS system monitor in your menu bar.
psutil - psutil is a module providing an interface for retrieving information on all running processes and...