Apple CUPS

CUPS is the widely used printing system for UNIX-like operating systems that presents a modern, network-centric print stack built around IPP. It includes the scheduler (the print server), filters, backends, and PPD/driver plumbing needed to accept jobs, determine capabilities, rasterize or convert, and deliver output to devices over local and network transports. Its modular pipeline lets administrators and vendors plug in drivers or filter chains while retaining a consistent user-facing interface across platforms. Client tools and libraries provide command-line and programmatic access for queue management, job submission, and printer discovery. Over time CUPS has aligned closely with driverless printing via IPP-Everywhere/AirPrint-style capability exchange, reducing the need for vendor-specific drivers on many devices. The project’s reference implementation is battle-tested across desktops, servers, and embedded systems that expose print services to a network.