If your management balks, do the following:

1. Ask them if they like the rapid and safe development of their system.
2. If they say "No", then that's an answer.
3. If they say "Yes", then tell them what the cost would have been to hand-roll all the underlying modules. Estimate about 2-3 man-years (at least!) for DBI, CGI, XML::Parser, and others.
4. Ask them for your back-pay.
5. When they balk at that, tell them that this is the "cost" of using open-source software.
6. Let them compare for themselves the cost of closed-source vs. open-source.

------
We are the carpenters and bricklayers of the Information Age.

Don't go borrowing trouble. For programmers, this means Worry only about what you need to implement.

Please remember that I'm crufty and crochety. All opinions are purely mine and all code is untested, unless otherwise specified.