I'm curious when you say you're running on XAMPP -- unless that's a typo, that is a Windows application that encapsulates the LAMP stack for development purposes -- it is absolutely not intended to be used for production, and if you are in fact using that on your server I would suspect that has something to do with the slow performance. Also note that there are many security issues with running XAMPP on a production server -- seehttp://serverfault.com/questions/289 ... -and-ass..
Unfortunately, the commenter was apparently unaware XAMMP runs on 4 platforms - 3 of which are Linux/Unix - Linux itself (there its called LAMPP - remember referring to it as LAMPP???), Mac and Solaris (Sun). Yep - OSX is a shell - Mac's run Unix! http://osxfaq.com/Tutorials/LearningCenter/
The Linux variant is from the same source versions as Windows XAMPP, but works quite differently from an installation and location point of view as the OS'es are soooo different. It still has all the same 'features' but in *nix variants
Running XAMMP on a VPS is unusual, but it probably is/was an unmanaged VPS (works like a dedicated server - you put your stuff on it, and you are on your own...) That would fit the description.
And, no, I have no interest in correcting morons who don't ACTUALLY HAVE ANY FIRST HAND KNOWLEDGE (and that would be 80-90% of the time, LOL).
Don't worry - you're OK if you follow good lockdown procedures -
Remember that the 'Bravo' server you got that EC Guide info from is running XAMPP for Windows over on another desk there...
I used the same procedures I outlined there in the Guide (that's how I did the Guide stuff, trial and error on a real machine). Its a mere wisp of a machine running XP Home - but It hosts a couple of low traffic forums and 4 WordPress installations (all low traffic), + some of my development PHP and MySQL experiments, and my frequent XAMPP tests for this forum - no problemo.
Gee - I must be crazy, huh??
See ya, and have a happy holiday season