"You haven't cleared the water much though... You haven't offered your own definition though, so you really haven't added anything."
I don't think there is a need for me to provide my own definition of enterprise software to be able to contribute to this discussion. If enterprise software is a concept that everybody can come up their own definitions, then it clearly tells me that the concept is not well defined.
"The perl interpreter... might be considered enterprise software because you need them to make things work."
You are free to think this way, but that certainly does not prove that Perl interpreter or JVM is an enterprise software according to common sense, although they could be called enterprise software according to your own definition.