Apache may come with a variety of modules. To find out whats installed on your host, run the following:
bash-2.05a$ pwd /usr/local/apache/bin bash-2.05a$ ./httpd -l Compiled-in modules: http_core.c mod_env.c mod_log_config.c mod_mime.c mod_negotiation.c mod_status.c mod_include.c mod_autoindex.c mod_dir.c mod_cgi.c mod_asis.c mod_imap.c mod_actions.c mod_userdir.c mod_alias.c mod_rewrite.c mod_access.c mod_auth.c mod_so.c mod_setenvif.c mod_jk.c suexec: disabled; invalid wrapper /usr/local/apache/bin/suexec
There is a warning that suexec is disabled, but usually it is not important.
If you don't have access to the box, you may try upload a php script with the following contents:
<? phpinfo(); ?>
If you do a find for Loaded Modules on the output of that page you should see the list of apache modules.