I am always looking for any suggestions for improvements to the installer. I'm also curious how people are using it; is it just for personal development, or is there anyone using it to deploy to a group of desktops or servers?

According to the original message on the php.internals list, John based it off of the functionality of the installer of Phil Driscoll with extra features like selective installation of components, automatic configuration of the php.ini and that it's made as a MSI file (scriptable and open source).