As Rabbit said, Smarty is an incredibly versatile template engine for PHP. It supports template compilation (for faster parsing/script execution when templates must be rendered), template caching and a nifty feature called template configuration settings, which is explained in a basic manner by its name.
Perhaps their server went down for maitenance or something of that nature. Also, most subdomains on the php.net domain (other than the ones that specify a mirror, such as us2.php.net) are hosted external from the PHP infrastructure, I think. PEAR is another one like this (which, incidentally, seems to be working fine).