The OC Cluster analysis program.
OC implements single, complete and means linkage cluster analysis. It does not have software limits on the number of entities that can be clustered.
OC was developed to cluster large sets of protein sequences, but it is general and can be applied to any type of data.
Version 2.1(February 2004) includes more options for postscript page layout.
Version 2.0 (August 2002) includes functions gjnoc and gjnoc2 that allow the OC software to be called from a C program.
Citing OC: OC does not have a formal publication, but if you use it in your work, please cite it as::
Barton, G.J. (1993, 2002) "OC - A cluster analysis program", University of Dundee, Scotland, UK;
Download OC here.