CUPS

The software implements a standards‑based printing system that uses the Internet Printing Protocol (IPP) to handle jobs for both local USB and network printers, including AirPrint and IPP Everywhere devices. It supplies traditional command‑line interfaces (System V “lp” and Berkeley “lpr”), a configurable web administration console, and a C API, together with a set of common filters, drivers, and backends. Legacy printers are supported via PPD files, while newer printers can be managed through driver‑less “everywhere” drivers or Printer Applications.

It is intended for administrators and users of Linux and other Unix‑like operating systems who need to manage printers and print queues on a self‑hosted server. The web interface at http://localhost:631/admin/ and the lpadmin command allow creation, configuration, and monitoring of printer queues, with access control based on system groups such as lpadmin.

The project is open source, released under the GPL‑2.0 license with an Apache‑2.0 exception for linking, and is maintained as a stable, self‑hostable component without subscription or tiered pricing. It includes extensive documentation, build instructions, and a suite of sample PPD files for common legacy devices.