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.
Note: A subset of Karabiner's functionality which is compatible with macOS 10.12 has been released, and can be found in Related Links.
- The initial key repeat rate of Karabiner will be set the slower value if you have not changed the key repeat rate in System Preferences.
- Karabiner does not save preferences properly in an edge
- OS X 10.9 or later