In all versions we updated Apache to 2.2.8, PHP4 to 4.4.8 and phpMyAdmin to 2.11.4. The Linux and Mac OS X versions contain also updated Perl (5.10.0) and MySQL (5.0.51a) releases.
Get the downloads and more details on the specific platforms XAMPP project page.
Kai 'Oswald' Seidler
New XAMPP version for Linux, Windows, and Mac OS X
XAMPP project page