vJoy was initially designed to provide an open-source replacement for PPJoy, a joystick emulator.

vJoy, at this point, consists of virtual joystick devices that are seen by the system as a standard joystick but its position-data is written to it by a feeder application. An existing feeder application that takes advantage of this product is SmartPropoPlus.

If you are an application writer, you can very quickly write an application that controls a joystick (e.g., mouse-to-joystick, keyboard-to-joystick). If you are a beginner in device drivers, you can take this code and enhance it to support more (or less) axes, buttons or POVs.

vJoy Features:

Virtual Device and device driver 32/64 bit
Driver is signed
Configurable: Up to 8 axes, up to 128 buttons, and optional 4 POV Hat Switch
Package include: Unified x86+x64 installer
Downloadable: Full sources, SDK (C/C++ C#), Demo feeder applications, documentation
Typical audience: Application writers that want to emulate joystick behavior