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.