The Common UNIX Printing System (or CUPS(tm)) is a printing system and general replacement for lpd and the like. It supports the Internet Printing Protocol (IPP), and has its own filtering driver model for handling various document types.

Diagnostics is a unified framework for code annotation, logging, program monitoring, and unit-testing.

This library contains common/shared code regarding the A-bis interface between the GSM Base transceiver station (BTS) and the GSM Base station controller BSC.

Eclipse Cyclone DDS is a very performant and robust open-source implementation of the Data Distribution Service (DDS) standard by the Object Management Group (OMG) and the related wire protocol for interoperability (RTPS). It is developed completely in the open as an Eclipse IoT project with a growing list of adopters, and has become a tier-1 middleware for the Robot Operating System (ROS 2).

Eclipse Cyclone DDS is a very performant and robust open-source implementation of the Data Distribution Service (DDS) standard by the Object Management Group (OMG) and the related wire protocol for interoperability (RTPS). It is developed completely in the open as an Eclipse IoT project with a growing list of adopters, and has become a tier-1 middleware for the Robot Operating System (ROS 2).

czmq (previously known as libzapi) provides a high-level C binding for 0MQ, a lightweight messaging library.