MySQL client libraries and headers are not included with Mac OS X Server 10.5. If you are developing a MySQL client application for Mac OS X 10.5, you'll need to download the MySQL client libraries and headers.
The MySQL client libraries and headers are available for download and installation from (http://www.opensource.apple.com/darwinsource/Current/).
To install:
Important: Information about products not manufactured by Apple is provided for information purposes only and does not constitute Apple's recommendation or endorsement. Please contact the vendor for additional information.