Pointless
The pointless program (see Scaling and Assessment of Data Quality, Philip Evans, Acta Cryst D 62, 72-82) serves to identify space group possibilities from unmerged data. It may be obtained from ftp://ftp.ccp4.ac.uk/ccp4/6.0.2/prerelease/ but the version at ftp://ftp.mrc-lmb.cam.ac.uk/pub/pre/ is the newest (versions before 1.2.13 have a bug which makes them crash on certain XDS_ASCII.HKL files). HTML documentation is at ftp://ftp.ccp4.ac.uk/ccp4/6.0.2/prerelease/pointless.html
Typical usage is
pointless xdsin XDS_ASCII.HKL
See also: xprep