UniDrv (Universal Printer Driver or Unidriver) is a GDI-based Microsoft Windows universal printer driver and architecture for non-PostScript printers. It is used to simplify driver development of non-PostScript printers (also called Winprinters) for printer manufacturers. Unidrv allows the creation of a printer-specific minidriver in the form of a GPD (Generic Printer Description) file, similar to a PPD file, which is much simpler than kernel mode driver development. Unidrv was introduced in Windows 2000 and replaced the Raster Device Driver (RASDD) interface used in Windows NT 4.0 and earlier versions.