On Mac OS X (Snow Leopard), I installed CentOS 5.6 as a development server on VirtualBox.

The installation procedure can be followed by simply following the reference articles.

VirtualBox Installation Reference Articles

・Local Development Environment with VirtualBox 2.2 and CentOS 5.3 - Bean Sprout Diary

Reference Articles for Installing CentOS in Virtual Environment

・[Virtual OS] Installing CentOS on VMware Player as a Development Server | CodeNote.net

Other Reference Articles

・Usability of Mac OS X Version VirtualBox

・Tried Installing CentOS 5.5 on VirtualBox - TANAKAORIGINAL

That’s all.

That’s all from the Gemba.