USound (the Useful Sound Daemon) is an audio I/O daemon for Unix systems, especially GNU/Linux. It provides low-latency mixing of multiple audio streams with resampling and limited format conversion, as well as audio recording. The package also includes a client library, a libao plugin, and patches for madplay and MPlayer. USound is free software; it is distributed under the GNU General Public License (GPL), except for the client library, which is in the public domain. USound is somewhat similar to the Enlightened Sound Daemon (EsounD); but as the name implies, USound aims to be more useful, particularly for consumer desktop and multimedia applications. Applications for which USound is suitable include media players, audio and video conferencing software, text-to-speech software, and any application that plays the occasional sound file to alert the user. USound is still under development and by no means perfect, but in my (admittedly biased) opinion, it has already surpassed EsounD and aRts in usefulness. The USound home page is at: http://pobox.com/~mattcampbell/usound/ Have fun! Matt (who is listening to an MP3 with USound and madplay right now)