These files are not necessary to run our main program - you can delete them;
however, you may optionally use them as additional free tools to have extra error-diagnostic information and/or conversion choices.

The communications between our main program and these optional tools are strictly restricted as:
"Our main program 'only launches' these executables with simple command-line arguments, not exchanging any internal data structure."

This way, our main program makes sure not to infringe any of their licenses, such as GPL, these additional free tools may have.
(http://www.gnu.org/licenses/gpl-faq.html#MereAggregation)

