EsounD, the Enlightened Sound Daemon, is a server process that mixes
several audio streams for playback by a single audio device. For
example, if you're listening to music on a CD and you receive a
sound-related event from IM client, the two applications won't have to
queue for the use of your sound card.
The daemon functionality was replaced with PulseAudio (PA) and the binary
was dropped from Fedora in October 2007. However, on PA-disabled systems
the daemon functionality was completely missing and therefore
reintroduced to Fedora in June 2013 in form of subpackage.
The daemon cannot run on PA-enabled systems.