What are some alternatives?
When comparing SharpKeys and X-Mouse Button Control, you can also consider the following products
Karabiner - Karabiner, previously called KeyRemap4MacBook, is a very powerful keyboard remapper for Mac OS X.
ControllerMate - Dec 2, 2017 - ControllerMate building blocks are triggered by controls on devices or MIDI messages. Each type of building block performs a small task. Building blocks can be combined to perform complex functions.
Key Remapper - Intended for remapping keys, mouse buttons and mouse wheel actions, Key Remapper allows you to:
Key Manager - ATNSOFT Key Manager, Key Remapper, Text Paster
SteerMouse - Advanced driver for USB and Bluetooth mouses.
Microsoft keyboard layout creator - Edit the windows keyboard layout.