XAMPP is a great suite to quickly get up and running with Apache, PHP, Perl and MySQL. Warning! It is not aimed to be used in a production environment! Its settings are geared towards ease of use rather then security!
However I went against my own advice and used it in a couple of instances, however these are not public facing sites, rather internal and heavily firewalled services. Even so whenever a security update to PHP comes out, I feel the need to use the new version. Here is how you can do it, without waiting for the official XAMPP package to update (you really can't criticize them for not updating faster, since it is a development not a production server and as such minor PHP releases shouldn't influence your code).
Warning! Use these instructions on your own risk. They are written to the best of my knowledge, however I can't make any guarantees. Always backup your data.