PHP's has mature URI parsing using several built-in functions that provide very similar functionality.

parse_url http://us.php.net/parse_url for getting URI components

parse_str http://us.php.net/parse_str for getting query string variables

These two functions take care of the vast majority of my URI parsing/creation tasks.

Of course it would be nice to have a fluent interface like URI.js via a PHP class. And the URI normalization functions.