Arguably, CapsLock is the most useless key on your keyboard. I honestly can’t remember the last time I had a real use for it. If are a programmer, you should remap it to something more useful. The rest of this post will describe how to remap your CapsLock on a Mac OSX installation.

What we are going to do

I’m a heavy vim user and reaching for the Esc key all the is a pain. We will remap the CapsLock to Esc. However, I want to be able to use it for something else if I’m not in vim. We will set it up so that when you hit CapsLock on its own, it will send Esc. However, if you hold CapsLock and press another key, it will send Ctrl. That way you can do things like Ctrl+F, etc.

On Mac OSX, you will want to do use Karabiner. It’s an excellent piece of software that will allow you to take control of your keyboard.

Settings

Once you have installed KeyRemap4MacBook, go to System Preferences and select the Keyboard submenu. Hit the Modifier Keys button and remap CapsLock to Ctrl. You will have to do this once for every keyboard that you use.

Next, head over to the KeyRemap4MacBook settings. The magical setting you are looking for is

Control_L to Control_L
    (+ When you type Control_L only, send Escape)

That’s it!