"I spoke with Zeev Suraski, co-founder and CTO at commercial PHP
vendor Zend Technologies last month about PHP 5.3. He noted that
one key feature backported from PHP 6 into PHP 5.3 is namespaces,
which is a way to encapsulate classes and other PHP items more
easily.
"While the official release is on June 30th, support for PHP 5.3
is already present in development tools from Eclipse released this
week."