Apache::VMonitor 2.x works with both mod_perl (Apache 1.x) and mod_perl2 (Apache 2.x).

To build:

  % perl Makefile.PL 
  % make
  % make test
  % make install

It should auto-detect which version you have and where your httpd is installed. If 
this does not work, you need to specify the location of your apache binary as
follows:

  % perl Makefile.PL -httpd <path to httpd>

If you have both installed you need to decide which version of mod_perl to build
it for.

  % perl Makefile.PL MOD_PERL=1

or 

  % perl Makefile.PL MOD_PERL=2