>Hi,
>
>I am confused on the following issues on Open source software
>
>* If I get Mysql for use with my own written application.
>When my customer purchased my software and want to use MySql
>in their company, do my customer had to pay for the use of MySql ?

From the MySQL.org download page.

You need to purchase commercial non-GPL MySQL licenses:

If you distribute MySQL Software with your non open source software,
If you want warranty from MySQL AB for the MySQL software,
If you want to support MySQL development.