What are some alternatives?
When comparing Key Remapper and Karabiner, you can also consider the following products
SharpKeys - SharpKeys is a utility that manages a Registry key that allows Windows to remap one key to any...
Key Manager - ATNSOFT Key Manager, Key Remapper, Text Paster
Microsoft keyboard layout creator - Edit the windows keyboard layout.
AutoHotkey - Free keyboard macro program. Supports hotkeys for keyboard, mouse, and joystick. Can expand abbreviations as you type them (AutoText).
X-Mouse Button Control - XMouse Button Control (XMBC) allows you to create application and window specific profiles.
KbdEdit - Keyboard layout editor, mapper/remapper.