Enterprise software for me tends to mean, very flexible and very scalable. Let's take perl and php sans mod_perl and the php cachers out there. As a "web language", it's not enterprise level. But even then, perl has its advantages in how flexible it is. Flexibility gives it more power, 'casue in today's day and age, less flexible software, like dbase, isn't helpful. We need replication. Relational capabilities. Live backups.
Peoplesoft is big because of this. They have a mamoth piece of software that's flexible to a point, and they have consulting services to further that felixibility. Apparently, it's also quite scalable too.
Have you looked into vendor assistance in what contracts you are about to forge? Like a 1 month, reduced cost setup thing?