DISTANCES is a FORTRAN77 program which reads a multiple alignment file in PIR or FASTA format, computes the distance matrix determined by the alignment, and writes that matrix to a file.
DISTANCES is available in a FORTRAN77 version and a FORTRAN90 version.
READ_ALIGN is a FORTRAN90 program which can reformat an alignment file so that it can be examined by DISTANCES.
SPACER is a FORTRAN90 program which can read the distance matrix created by DISTANCES and perform a principal component analysis.
SPACER_DATA_CONVERT is a FORTRAN90 program which can read a multiple sequence alignment file and write out the relevant information into a file in PIR format.
Des Higgins,
EMBL Data Library
You can go up one level to the FORTRAN77 source codes.