PHP is an open source general-purpose server-side scripting language originally designed for Web development to produce dynamic Web pages. It is one of the first developed server-side scripting languages to be embedded into an HTML source document rather than calling an external file to process data. The code is interpreted by a Web server with a PHP processor module which generates the resulting Web page. It also has evolved to include a command-line interface capability and can be used in standalone graphical applications.

If you are new to PHP and want to get some idea of how it works, try the introductory tutorial.

After that, check out the online manual.

What's New:

  • Added constant scalar expressions syntax.
  • Added dedicated syntax for variadic functions.
  • Added support for argument unpacking to complement the variadic syntax.
  • Added an exponentiation operator.
  • Added phpdbg SAPI.
  • Added unified default encoding.
  • The php://input stream is now re-usable and can be used concurrently with enablepostdata_reading=0.
  • Added use function and use const..
  • Added a function for timing attack safe string comparison.
  • Added the __debugInfo() magic method to allow userland classes to implement the getdebuginfo API previously available only to extensions.
  • Added gost-crypto (CryptoPro S-box) hash algorithm.
  • Stream wrappers verify peer certificates and host names by default in encrypted client streams.
  • Uploads equal or greater than 2GB in size are now accepted.

Complete release notes here.