At my last job I was in charge of a project to rebuild an ecommerce transaction system in Perl.

This invloved a Perl based server cluster (i.e: servers written in Perl communicating with each other), CGI apps running under apache and various security and reporting tools. The CGI calls went in and around the servers and through to the database or to the banks to process the credit card.

The cluster had (at that time) 4 tiers of operation with each tier able to communicate to the tier on either side.

Additionally, the whole admin and reporting system used HTML::Template (at the time I was there).

This system provided the technology for the core part of the business which was to process credit cards. Hence without this system there would be no business.

I don't know how they support Perl at that company as I no longer work there but I suspect that apart from buying books and advocating the language to clients/workers there is little else done.