Can I use XAMPP for a commercial product?

[skewedToTheLeft]

Hi,
A dentist has contracted me to create a database system that he wants to be able to sell to other dentists. He wants it to work on both the Windows and Mac platforms. I realize there are different versions of XAMPP for Windows and the Mac. I would be using Apache, php and MySQL to create the database system. My question is since he wants to sell this system, will this action violate the license agreement for using XAMPP and its contained components? If so, is there a commercial license available to use this product with its contained components in a commercial environment and how much is the license?