This is a simple, rather lame spectrum analyzer made from the fix_fft.c code, as found I think in xmms-0.9.1 (the 75-wide output sounds like xmms to me), which is actually written by other people (see fix_fft.c for credits). It worked last time I had GiST working, which was a while ago. Yes, GiST is not included here yet, it will be in 0.1.0.