compcomm - two papers from IUCr computational crystallography authored by Ralf with some scripts. These scripts are referenced in these papers. One paper in LaTeX by Luc Bourhis "Small-molecule toolbox".
dox - probably was meant as documentation, actually contains some documentation in RST, Ralf's talks from Siena, 2005, some tutorial in LaTeX, the content for the cctbx website.
fftw3tbx - probably is not used anywhere
ipctbx - most likely is not used anywhere, wrapper for sys/ipc.h - C library for interprocess communication access structure.
rpmbuild - not sure whether it is still needed/working, last change to the only file was on 7-29-2009.
setup - not clear whether the only .sh script in this directory is still needed/working.