Around one month ago, version 5.3 of the popular scripting language PHP was released.
PHP 5.3 is not enabled by default, because many web applications need to be modified or updated. For example, many warnings may arise regarding features that have been deprecated. These are functions that are being phased out, and which probably will not work in PHP 6.0. It’s possible to select for each domain whether to use PHP 5.2 or PHP 5.3, but new domains are still defaulting to PHP 5.2. This way it’s easy to test if a given site works with PHP 5.3, but with the option to quickly switch back to PHP 5.2 in case of any problems.