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 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