How to remap Caps Lock to Left Control.
Why? Because it is more ergonomic, and the default function of the Caps Lock key is pretty meh.
Debian/Linux (and probably other linuxes)
# /etc/default/keyboard
# KEYBOARD CONFIGURATION FILE
# Consult the keyboard(5) manual page.
XKBMODEL="pc105"
XKBLAYOUT="us"
XKBVARIANT=""
XKBOPTIONS="caps:ctrl_modifier"
BACKSPACE="guess"Windows
Use SharpKeys