PHP, the PHP Hypertext Processor, is an open source server-side scripting language for Web servers, which provides a real alternative to ASP, ColdFusion, Mod_Perl or JSP if your aim is to provide dynamic Web pages. Dynamic Web pages are pages which interact with the user, so that each user visiting the page sees customized information - which may vary each time and which may be based on a form they've just filled in, or on information extracted from a database or some other external source. Typical applications include e-commerce, online newspapers, visitors' books, ticketing systems, project management, and other groupware projects. The traditional way to produce this type of dynamic page is via CGI scripts, but these are separate programs which must be executed as a new process for each page hit, so they scale badly and rapidly become memory and processor hogs as server load increases...