A number of things can be accomplished with it. This documentation 
excerpt indicates the capabilities:

Quick summary of the parameters/tools:
     -infile              file that is used for input, where applicable
     -outfile             file that is used for processed output, where 
applicable
     -record_type         whatever you're doing, look only at the 
specified record type
     -manual_edit         process infile to enable editing via any text 
editor
     -finish_manual_edit  convert manually edited file back to MARC format
     -create_filters      selectively process input based on 
field/subfield/indicators
     -filter_file         switch from standard to specified filter file, 
or turn filter off
     -create_actions      for leader, any field/subfields: 
add|delete|copy|relabel|replace
     -delete_action       remove an action from standard actions file
     -use_action          apply the specified action
     -update005           optionally update 005 when an action changes a 
record
     -action_file         switch from standard to specified action file
     -no_actions          absolutely do not do anything with any actions
     -create_ctl_file     store parameters for easy reuse of a common 
application
     -use_ctl_file        specifying this parameter invokes the stored 
parameters
     -output_edits_only   output only those records changed by an action
     -dryrun              do an action run-through without changing anything
     -progress            real-time progress indicator suitable for 
larger files
     -segregate           split infile into separate files of bibs, 
holdings, authorities
     -dupe_finder         find field duplication within a record
     -get_field           prints all occurrences of the specified field 
to STDOUT
     -field_sifter        output records containing (or not) the 
specified field

It is available at: https://royzimmer.library.wmich.edu/marc_index.html

As it is a Perl program it does require Perl on your system and that's 
all it needs.