Apache Display / Change a Default Page Other Than index.html

How do I display or change a default page other than index.html or index.php under Apache web server?

You need to use DirectoryIndex directive under Apache to set a default page other than index.html or index.php.

The DirectoryIndex directive sets the list of resources or file to look for, when the client requests an index of the directory by specifying a / at the end of a directory name.

Edit httpd.conf

Open your Apache configuration file httpd.conf
# vi httpd.conf

Find out line that read as follows:
DirectoryIndex

Now set it as per your requirements:
DirectoryIndex index.html index.htm default.htm index.php index.pl

Save and close the file. Restart the Apache web server:
# /etc/init.d/httpd restart

Please note that if you do not have access to Apache configuration file. Add DirectoryIndex to your .htaccess file.

You can also specify php or pl dynamic script. Also note that the documents do not need to be relative to the directory. Consider following example
DirectoryIndex index.html index.pl /nav/index.php

Above would cause the php script /nav/index.php to be executed if neither index.html or index.pl existed in a directory.