WARNING

This script builds a package that conflicts with apache1. Before
attempting to install this package, you should uninstall any of
these packages that you find on your system:

apache
mod_ssl
php

Really though, the only points of overlap are in /usr/sbin, so if you
leave your old packages in place apache2 will still work, but the
apache1 httpd will have been overwritten (along with other files)

Apache is the most popular web server in the known universe; over half
the servers on the Internet are running Apache or one of its variants.

By default, we build apache2 with the traditional "apache prefork" multi
processing module (MPM). This is somewhat safer for the use of mod_php,
but can still carry some security risks (all your php scripts run as the
user configured to run apache2).

For enhanced multi-threaded performance, use "apache worker", but using
mod_php with "worker" is considered dangerous. PHP Core is multi-thread
safe, but many PHP extensions are *NOT*. To build apache2 with the
worker MPM, change the option to: --with-mpm=worker

Please note that this script does not build apache2 with SuEXEC support.
The Apache group feels SuEXEC should not be part of a default install.
If you need this functionality, please read the following documentation
and make the necessary changes to the ./configure options in the script.

http://httpd.apache.org/docs/2.0/suexec.html