Karabiner (was KeyRemap4MacBook) is an awesome utility for keyboard customization on OS X.
- You can re-map any key without any restriction.
- You can accelerate speed of the key repeat.
- 'Option::FLIPSCROLLWHEEL_HORIZONTAL' and 'Option::FLIPSCROLLWHEEL_VERTICAL' have been supported in '__PointingRelativeToScroll__'.
- Remote Desktop detection would fail in some cases.
- Settings for input-source switching did not work in some environments.
- OS X 10.9 or later