i3status is a small program for generating a status bar for i3bar, dzen2,
xmobar or similar programs. It is designed to be very efficient by issuing a
very small number of system calls, as one generally wants to update such a
status line every second. This ensures that even under high load, your status
bar is updated correctly. Also, it saves a bit of energy by not hogging your
CPU as much as spawning the corresponding amount of shell commands would.