You now install freebsd from either a package or /usr/ports, which is a method for creating packages as well. From the early adopters page on freebsd 5...

Perl has been removed from the base system, and should be installed either from a pre-built package or from the Ports Collection. Building Perl as a part of the base system created a number of difficulties which made updates problematic. The base system utilities that used Perl have either been rewritten (if still applicable) or discarded (if obsolete). sysinstall(8) will now install the Perl package as a part of most distribution sets, so most users will not notice this change.

The dependencies seem to solely be on shell and c. Maybe c++, but I haven't looked for the c++ to be definite. It's not in a move to distance itself from perl, just to have smaller number of tight dependencies. Thought I have to say, /usr/ports has a nice configuration management when it comes to installing perl modules. It's not as large as CPAN though.

Mac OSX just comes with perl. It does get upgraded through software update. It comes with a few scripting languages by default. tcsh, python and ruby (aside from perl).