Hardware Lister - lshw (Hardware Lister) is a small tool to provide detailed information on the hardware...
iStat Menus - "An advanced Mac system monitor for your menubar."
Stats - Simple macOS system monitor in your menu bar.
Speccy - Speccy - find the details of your computer's specs. Great for spotting issues or finding compatible upgrades. Download the latest version free.
MenuBar Stats - Advanced Mac system monitor right from the menu bar
Psensor - Psensor is a graphical hardware temperature monitor for Linux.