How to hook/remap an arbitrary keyboard event on OSX?

Question

I would like to map:

• CAPS-LOCK to Fn
• Fn to Left-MOUSE
• LSHIFT+3 to #

Answer 1

Have you checked out Karabiner (which does all that you want to do.. up till OSX 10.11 .. MacOS 10.12 changed the keyboard driver model, and the authors - mainly Tekezo- are still re writing Karabiner to take account of the new model - this is as of feb 2017) Karabiner is open source, and you can download the code from Github and twiddle with it.

As part of the re-write they have released Karabiner-elements which works on 10.12 Sierra, but cannot yet do everything that karabiner did.

Karabiner is very powerful, and I miss it greatly on 10.12