This developerWorks article discusses how XML is becoming huge in the P2P world, citing that "Virtually all emerging P2P platforms rely on XML". However XML lacks durable end-to-end security architecture, a point this author believes may be solved by Web services protocols.
PHP started as a quick Perl hack written by Rasmus Lerdorf in late 1994. Over the next two to three years, it evolved into what we today know as PHP/FI 2.0. PHP/FI started to get a lot of users, but things didn't start flying until Zeev Suraski and Andi Gutmans suddenly came along with a new parser in the summer of 1997, leading to PHP 3.0. PHP 3.0 defined the syntax and semantics used in both versions 3 and 4.
Source: PHP Builder
From preface of the PHP manual, the following states the definition of PHP scripting: "PHP is an HTML-embedded scripting language. ... The goal of the language is to allow web developers to write dynamically generated pages quickly."