htop - htop - an interactive process viewer for Unix. This is htop, an interactive process viewer for Unix systems. It is a text-mode application (for console or X terminals) and requires ncurses. Latest release: htop 2.
iStat Menus - "An advanced Mac system monitor for your menubar."
Stats - Simple macOS system monitor in your menu bar.
Process Explorer - The top window always shows a list of the currently active processes, including the names of their owning accounts, whereas the information displayed in the bottom window depends on the mode that Process Explorer is in: if it is in handle mode you'l…
MenuBar Stats - Advanced Mac system monitor right from the menu bar
Beaconly - Flexible, easy to use data aggregating menu app that ties relevant information in a macOs menu bar.