CUPS provides a portable printing layer for UNIX(r)-based
operating systems. It has been developed by Easy Software
Products to promote a standard printing solution for all UNIX
vendors and users. CUPS provides the System V and Berkeley
command-line interfaces.

CUPS uses the Internet Printing Protocol ("IPP") as the basis
for managing print jobs and queues. The Line Printer Daemon
("LPD") Server Message Block ("SMB"), and AppSocket (a.k.a.
JetDirect) protocols are also supported with reduced
functionality. CUPS adds network printer browsing and
PostScript Printer Description ("PPD") based printing options to
support real-world printing under UNIX.

CUPS includes an image file RIP that supports printing of image
files to non-PostScript printers. A customized version of GNU
Ghostscript for CUPS called ESP Ghostscript is available
separately to support printing of PostScript files within the
CUPS driver framework. Sample drivers for Dymo, EPSON, HP, and
OKIDATA printers are included that use these filters.