Howtoforge posted a guide about installing CentOS 5.7 x86_64 with ISPConfig 3

This tutorial shows how to prepare a CentOS 5.7 x86_64 server for the installation of ISPConfig 3, and how to install ISPConfig 3. ISPConfig 3 is a webhosting control panel that allows you to configure the following services through a web browser: Apache web server, Postfix mail server, MySQL, BIND nameserver, PureFTPd, SpamAssassin, ClamAV, and many more.

  The Perfect Server - CentOS 5.7 x86_64 (ISPConfig 3)