There is an Apache module available which shows a detailled page with various settings and the active configuration.
mod_info is disabled by default and must be enabled with ./configure --enable-info when building Apache. On Debian and Ubuntu, this module and its configuration can be enabled using sudo a2enmod info.
Put the next lines in your configuration file (httpd.conf) (not necessary when using a2enmod):
<Location /server-info>
SetHandler server-info
</Location>
After restarting the server, the configuration file is available at http://example.com/server-info?config (replace example.com with your server address)
Note that this information is quite sensitive, you might want to restrict access as in:
<Location /server-info>
SetHandler server-info
Order deny,allow
Deny from all
Allow from yourcompany.com
</Location>
For more information, see http://httpd.apache.org/docs/2.2/mod/mod_info.html