What are some alternatives?
When comparing DS4Windows and JoyToKey, you can also consider the following products
Xpadder - Xpadder simulates the keyboard and mouse using your gamepad What does Xpadder let you do?
AntiMicro - A tool for mapping keyboard and mouse events to gamepads and joysticks.
Pinnacle Game Profiler - Pinnacle Game Profiler enables the use of virtually any game controller (gamepad, joystick, etc.) with any PC game. It's preconfigured for most game titles and controllers. Just download and play.
reWASD - First and only gamepad mapper to make Xbox Elite paddles separate buttons.
InputMapper - Input Mapper is designed to bridge the gap between the devices you use and the games you play.
ScpToolkit - Windows Driver and XInput Wrapper for Sony DualShock 3/4 Controllers. SourceForge is not affiliated with ScpToolkit.