You must add one of the following to your apache config to activate
mod_perl:

  # Apache 2.0
  LoadModule perl_module libexec/apache2/mod_perl.so

  # Apache 2.2
  LoadModule perl_module libexec/apache22/mod_perl.so

For a more detailed version (including more options) refer to:

  docs/user/intro/start_fast.pod
