Well on the surface there is not much difference.
The obvious difference is in the names
WAMPServer install Apache,MySQL,PHP
while with XAMPP you get an extra P
XAMPP install Apache,MySQL,PHP,Perl
The thing that swung it for me is that I develop in PHP and for many different people, so I need to be able to setup an environment that matches that of my Clients server.
With WAMPServer this can be done, with XAMPP it is not part of there ethos, as its developed by the Apache community its versions of Apache/PHP/MySQL are more ridgid i.e. you get a specific version of all those parts with a single version of XAMPP and switching is just not an option (unless you know what you are doing.
With WAMPServer I can have many versions of Apache, many versions of PHP and many versions of MySQL all installed. It is then just a case of switching versions of any of those to match my requirement. The switch is just a click on a menu. Of course the installation of many versions does take space and is not as easy as it once was, as you have to do it manually now for reasons that are not relevant here.
Well anyway if you want Perl, then XAMPP is the simplest solution, although it can be configured in WAMPServer but its all man-draulic.
If Perl is irrelevent but flexibility is useful WAMPServer is the better choice.
Oh just one last thing, the latest versions of Apache etc are compiled with Visual C++ 2012 (VC11) and therefore will not run on Windows XP as the required C/C++ runtime library will not install on XP, but that applies to both WAMPServer and XAMPP.
I hope this is of some help to you in making a decision.
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(Windows 10 Pro 64bit) (Wampserver 3.3.4 64bit) Aestan Tray Menu 3.2.5.4
<Apache versions MULTIPE> <PHP versions MULTIPLE> <MySQL Versions MULTIPLE>
<MariaDB versions MULTIPLE> <phpMyAdmin versions MULTIPLE> <MySQL Workbench 8.0.23>Read The Manuals Apache --
MySQL --
PHP --
phpMyAdminGet your Apache/MySQL/mariaDB/PHP ADDONs here from the
WAMPServer alternate Repo-X-X-X-
Backup your databases regularly Here is How dont regret it later! Yes even when developing -X-X-X-