D-Bus is a technical specification for a inter-process communication (IPC) system, allowing multiple, concurrently-running computer programs (processes) to communicate with one another. D-Bus was designed as part of the effort of the freedesktop.org project to standardize services provided by Linux desktop environments such as GNOME and KDE. The freedesktop.org project also developed a reference implementation of the specification called libdbus, as a free and open-source software library. Other implementations of D-Bus also exists, such as GDBus[3] (GNOME), QtDBus[4] (Qt/KDE) and dbus-java.[5]