I think perl -V will return the OS it was orginally built under, not what is currently running. ActivteState building under NT 4.0 makes sense, since there are still a good chunk of NT4 servers out there that wouldn't be able to run a version built on Win2k (just a guess).

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I wanted to explore how Perl's closures can be manipulated, and ended up creating an object system by accident.
-- Schemer

Note: All code is untested, unless otherwise stated