On December 31, 2007 the PHP Group discountinued support for PHP 4. Since then, there have been no updates to the branch, security or otherwise. PHP 5 is the currently supported branch, and it is far superior to its predecessor.
Web hosts have, for quite some time, delayed upgrading their servers to PHP 5, despite its many advantages. (SimpleXML and better tools for OOP are just a couple invaluable tools that PHP 4 lacks.) Their favorite claim is that it will break everyone’s scripts.
The only scripts that PHP 5.2.x would break are badly-written ones. Popular packages such as WordPress, Joomla, phpBB all work on PHP 5, and some are even dropping support for PHP 4. The only scripts that will have compatibility issues are custom badly-written scripts, and the required updates would be minor. One of the biggest issues would be register_globals, and that could be remedied with some quick updates to scripts, or by turning it back on.
It’s been put off long enough. Web hosts, upgrade to PHP 5 already! The time is long past due.
