Wordpress - WAMP vs XAMPP pros/cons - for running a local testing server
XAMPP is NOT cross-platform. There is XAMPP for Windows, XAMPP for Linux, for Mac and for Solaris, but each pack contains different pieces of software, runs differently with different performance, etc. (cross-platform means that you take the exact same piece of software and it runs the same way on different platforms ... like Azureus used to be: a jar that you could use the same way)
XAMPP for Windows is bloated, big time. You have mail server, FTP server, accelerator, web-dav, SSL out of the box, etc. Do you really need them all? It's not exactly an entry-level package, but in general it makes installation of everything much easier. Beyond that, any customization requires the same effort as for any other pre-made stack. But if you install on your own box, you probably don't need FTP server, do you?
WAMP is lighter (mostly the basics). Everything that's AMP is there, beyond that you have a couple of tools, phpMyAdmin, SQLite, and xdebug. Do you need SSL? You have to configure it. You want access to mail server? Must install it yourself. FTP? Ditto.
WAMP (like the name says) runs only on Windows (either 64/32-bit).
For a local machine on Windows, WAMP is the way to go. Light, smooth and post-install configuration takes a click. XAMPP for Windows isn't much of a competitor due to issues on 64-bit installation (naturally: more bloatware to install, and you need to manage each piece of extra software between 32/64-bit).
Biggest difference - WAMP runs on Windows, XAMPP is multi-platform. Aside from that it's a matter of personal preference. They both provide you with an Apache-MySQL-PHP environment that runs pretty much the same under both systems.
WAMP is an acronym that means: Windows, Apache, MySQL, and PHP.
There are different WAMP "distributions", such as XAMPP, WampServer (what some people just call "WAMP"), Wamp-Developer Pro (commercial software), and others...
XAMPP for Windows is just another WAMP distribution, nothing more (nor something else).