How to identify which type of Apache is installed?

Hi,
I need to find out which type of Apache is installed.
following is the list of Apache types
Covalent,
IBM HTTP,
HP Apache-based,
Oracle,
Stronghold
and may be some other as well.
If anyone know how to figure out this, please share it with me.

Thanks
Sarwan

~httpd -v
e.g.
#/usr/local/apache2/bin/httpd -v
Server version: Apache/2.2.4 (Unix)
Server built: Sep 18 2007 15:26:20

It shows only the version but there is no type information.
Server version: Apache/2.2.0
Server built: Mar 31 2006 14:36:43

#cd /usr/local/apache2/bin/
# file httpd