I rather have to agree with itub on this, with the possible exception of a database of some sort. It seems to me that 'Enterprise Software' is something that is used by everyone (like water) and cannot be done without. Oracle (or mysql enzovoort) fits this category, but perl does not. Nor, for that matter, do most software packages such as Word, Openoffice.org, accounting packages, satellite tracking or nuclear weapon targeting packages. Perhaps, though, an email 'system' might qualify as Enterprise?