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www.it-ebooks.infoCHAPTER 1 • INTRODUCING PHPNOWDOC syntax, version 5.3 represents a serious step forward in PHP’s evolution. Throughout thisbook you’ll be introduced to this compelling set of features.PHP 6As was mentioned earlier in the chapter, a new major version of PHP known as PHP 6 has beenconcurrently developed alongside PHP 5.X for several years, with the primary goal of adding Unicodesupport to the language. However, in March, 2010 the development team decided to primarily focus onthe 5.X series of releases. In fact, several features originally slated for PHP 6 have been integrated into 5.Xreleases. Although PHP 6 beta releases had previously been made available at http://snaps.php.net, atthe time of this writing it appears as if those releases have been removed from the PHP website.You’ll find that a great deal has been written about PHP 6 online and elsewhere, and you’ll even seea few programming books reference this forthcoming version within their titles; my advice is to ignorethe matter altogether until the official PHP development team makes further announcements.So far, this chapter has discussed only version-specific features of the language. Each version sharesa common set of characteristics that play a very important role in attracting and retaining a large userbase. In the next section, you’ll learn about these foundational features.• Note You might be wondering why versions 4, 5, 5.3, and 6 were mentioned in this chapter. After all, isn’t onlythe newest version relevant? While you’re certainly encouraged to use the latest stable version, versions 4 and 5remain in widespread use and are unlikely to go away anytime soon. Therefore, having some perspectiveregarding each version’s capabilities and limitations is a good idea, particularly if you work with clients who mightnot be as keen to keep up with the bleeding edge of PHP technology.General Language FeaturesEvery user has specific reasons for using PHP to implement a mission-critical application, although onecould argue that such motives tend to fall into four key categories: practicality, power, possibility, andprice.PracticalityFrom the very start, the PHP language was created with practicality in mind. After all, Lerdorf’s originalintention was not to design an entirely new language, but to resolve a problem that had no readilyavailable solution. Furthermore, much of PHP’s early evolution was not the result of the explicitintention to improve the language itself, but rather to increase its utility to the user. The result is alanguage that allows the user to build powerful applications even with a minimum of knowledge. Forinstance, a useful PHP script can consist of as little as one line; unlike C, there is no need for themandatory inclusion of libraries. For example, the following represents a complete PHP script, thepurpose of which is to output the current date, in this case one formatted like September 23, 2007:5