PHP is a Web scripting language that is the functional equivalent of Microsoft's VBScript and Active Server Pages except that PHP is more platform-agnostic...PHP3 provides myriad powerful features for your Web applications.

Ask most Web application developers their scripting language of choice, and you'll find that most are divided into two camps - the Microsoft Active Server Pages (ASP) folks, and the Cold Fusion users. If you do a little more research however, you'll find there are other options out there, and one of these, PHP 3.0, is in much wider use than one would think for an "alternative product".