Server config: 

• letting Mason know to interpret *.html files

DocumentRoot /usr/share/my-site/htdocs

PerlSetVar MasonCompRoot /usr/share/my-site/htdocs
PerlSetVar MasonDataDir /var/cache/my-site/mason

<LocationMatch "\.html$">
    SetHandler perl-script
    PerlHandler HTML::Mason::ApacheHandler
</LocationMatch>

• Note: same DocumentRoot and MasonCompRoot