PHP.net: PHP 5.4.0 Released
The PHP project has just released the latest stable version of the language - the long-awaited PHP 5.4.
The PHP development team is proud to announce the immediate release of PHP 5.4.0. This release is a major improvement in the 5.x series, which includes a large number of new features and bug fixes. Some of the key new features include: traits, a shortened array syntax, a built-in webserver for testing purposes and more. PHP 5.4.0 significantly improves performance, memory footprint and fixes over 100 bugs.
They've also included a migration guide for the PHP 5.3 users out there to bump up to the next version. You can get this latest release from the main download page (source) or the Windows site for binaries.