The Ssindex.cmd script builds the list of files checked into source control along with the version information of each file. It stores a subset of this information in the .pdb files generated when you built the application. SSIndex uses one of the following Perl modules to interface with source control:
vss.pm (Visual SourceSafe)
tfs.pm (Team Foundation Servers)
For more information, run Ssindex.cmd with the -? or -?? (verbose help) option or examine the script.