slackbuilds/system/xosd

XOSD displays text on your screen; sounds simple, right? The
difference is that it is unmanaged and shaped, so it appears
transparent. This gives the effect of an On Screen Display, like
your TV/VCR etc. The package also includes an xmms plugin, which
automatically displays various interesting things as they change (song
name, volume etc...)

gdk-pixbuf is an optional dependency, but don't bother - it causes the
build to fail.