I agree with the above statements. In our case, the interface was the configuration files. So, our input files turned into small Perl scripts. Those that knew Perl could take advantage immediately and those that didn't could use the examples or small documentation we provided on how to write the input files.
It is important to note that this tool was for people who must program as part of their daily job. So maybe the Perl interface is a better match for that reason.
dragonchild alluded to this in the post above; for this to be truly effective, the users should be programmers.
