The PHP Development Team has announced the immediate availability of PHP 5.6.0

This new version release comes with new features, some backward incompatible changes and many improvements.

The main features of PHP 5.6.0 include:

Constant scalar expressions.
Variadic functions and argument unpacking using the ... operator.
Exponentiation using the ** operator.
Function and constant importing with the use keyword.
phpdbg as an interactive integrated debugger SAPI.
php://input is now reusable, and $HTTP_RAW_POST_DATA is deprecated.
GMP objects now support operator overloading.
File uploads larger than 2 gigabytes in size are now accepted.

For a full list of new features, you may read the new features chapter of the migration guide.

PHP 5.6.0 also introduces changes that affect compatibility:

Array keys won't be overwritten when defining an array as a property of a class via an array literal.
json_decode() is more strict in JSON syntax parsing.
Stream wrappers now verify peer certificates and host names by default when using SSL/TLS.
GMP resources are now objects.
Mcrypt functions now require valid keys and IVs.

For users upgrading from PHP 5.5, a full migration guide is available, detailing the changes between 5.5 and 5.6.0.

For source downloads of PHP 5.6.0, please visit our downloads page. Windows binaries can be found on windows.php.net/download/. The full list of changes is available in the ChangeLog.

  PHP 5.6.0 released