Recently the new version of PHP was released: version 5.2.0. It can be downloaded from the PHP.net site, as well as the changelist.

Some of the key features:

• New memory manager for the Zend Engine with improved performance and a more accurate memory usage tracking.
• Input filtering extension was added and enabled by default.
• JSON extension was added and enabled by default.
• ZIP extension for creating and editing zip files was introduced.
• Hooks for tracking file upload progress were introduced.
• Introduced E_RECOVERABLE_ERROR error mode.
• Introduced DateTime and DateTimeZone objects with methods to manipulate date/time information.
• Upgraded bundled SQLite, PCRE libraries.
• Upgraded OpenSSL, MySQL and PostgreSQL client libraries for Windows installations.
• Many performance improvements.
• Over 200 bug fixes.