MPDs

MPDs is an abbreviation commonly used to refer to multiple Music Player Daemon servers. Music Player Daemon (MPD) is a lightweight, server-side audio playback system designed for networked control. Each MPD instance manages its own library, playlist, and playback state, allowing different machines or users to run separate music servers within a single organization or home network.

MPD operates as a background daemon on Unix-like systems, with ports and sockets available for remote control. Clients connect to an MPD server via a simple text-based protocol over TCP (default port 6600) or Unix domain sockets. Through this protocol, clients can issue commands to start or stop playback, skip tracks, add items to the queue, manage playlists, and query the current status. The server maintains a library database, a playback queue, and an audio output pipeline that interfaces with various backends such as ALSA, PulseAudio, OSS, JACK, or CoreAudio, enabling broad hardware compatibility.

A typical MPD deployment involves a headless server running on a dedicated machine or device, with one or more client applications providing the user interface. Popular clients include command-line tools like mpc, graphical frontends such as Cantata, ncmpcpp, or ympd, and web interfaces. MPD’s design emphasizes minimalism, modularity, and remote control, which has contributed to a large ecosystem of clients and integrations across platforms.

The MPD project is open source and widely used in home media servers, embedded devices, and streaming setups. MPDs can be managed individually or synchronized across multiple servers, allowing centralized control of several distinct music libraries.