Core PHP Programming, Third Edition

1.5. Hardware and Software Requirements

One great advantage of Open Source software is that it provides the opportunity for adaptation to new environments. This is true of PHP. Although originally intended as a module for the Apache Web server, PHP has since abstracted its Web server interface. The new abstraction layer allowed an ISAPI module to be written, which allows it to work equally well with Microsoft's Internet Information Server. With regard to hardware requirements, I have personally witnessed PHP running on 100-MHz Pentium machines running Slackware Linux and Windows NT respectively. Performance was fine for use as a personal development environment. That the engines for PHP 3 and 4 were developed on Intel 486 CPUs must have helped. ...