PHP 5.5 (the latest stable build as of this writing) has made major progress from earlier versions. Recent PHP releases contain powerful new features and helpful developer tools, such as a built-in web server, generators for simpler iteration, and namespaces. With PHP 5.4, traits were introduced (a la Scala or Perl) to allow code reuse in single inheritance languages, as well as closures, which allow you to code PHP in a functional style. Other important features include the built-in FastCGI process manager and phpdbg debugger, and a new password hashing API that makes it easy to hash and securely manage passwords in PHP.
via The new PHP – Programming – O’Reilly Media.
Article highlights some of the major improvements to PHP as the language matures. Always good to know that my favorite language keeps getting better.