>both the applications
I believe you got it wrong:
Neither Wamp nor Xampp is an "application". These are both "distributions", that means they deliver a certain package of third party applications.
And they both deliver the SAME applications (Apache, MySQL, PHP), only the releases differ.
Its senseless to evaluate Wamp vs. Xampp, as you evaluate Apache vs. Apache, MySQL vs. MySQL, PHP vs. PHP etc. The only thing you compare, is (for example) Apache 2.0 vs. Apache 2.2, MySQL 4.1 vs. MySQL 5.0, PHP 5.1 vs. PHP 5.2. (or so - I dont actually know the releases of both packages). Especially your Xampp package is outdated, the actual release is Xampp 1.7.2, which contains Apache 2.2.12, MySQL 5.1.37, PHP 5.3.0 and some more tools and addons.