CUPS is a printing system that uses IPP to talk to printers and network clients. It also provides the old lp and lpr commands, a Web interface, and a C programming interface to manage printers and print jobs.

CUPS can print to both local (USB, serial, even parallel) and networked printers. Almost any modern printer supports IPP Everywhere, sometimes sold as AirPrint, and is supported out of the box. Older printers can be supported through legacy PPD-based printer drivers called ``printer applications''. These must be installed separately.