xmms-alarm is a plugin which allows XMMS to be used as an alarm clock. It features alarm start time, sleep time (so the alarm will stop after a while), volume fading time, loading a seperate playlist for the alarm, executing a shell command when the alarm goes off, and the option to choose a starting volume when fading.
xmms-crossfade is an output plugin for XMMS. Its main feature is automatic crossfading. It also removes the gaps between tracks, to play whole MP3 albums without any audible interruption. xmms-crossfade supports OSS via a builtin driver, and any other platform by using existing output plugins. As of version 0.3.9, the Audacious media player is also supported.
xmms-shn is an input plugin to play shorten (.shn) files in XMMS. It supports real-time seeking via the seek extensions built into shorten 3.x. Shorten is an audio compression format developed by SoftSound, and is used extensively in the distribution of losslessly-compressed live music.