PM123 1.41 alpha 1 has been released (6/16/2013); the alpha version does not replace the stable PM123 1.3.x.

This is an open source MP3, OGG, WAV, and CD Audio player. Some of the features of the alpha include gapless playback, nested playlists, and a PulseAudio client.
Source: OS/2 Warp News and Rumors