FM CreditCard for Mac

From Productive Computing:

FM CreditCard is a FileMaker Pro Credit Card Processing Plug-in that allows your users to easily process any credit card transactions. There is no limit to how many transactions you can process. Functions include authorize and capture sales, refunds and credits, voids and raw posts. The plug-in returns the approval codes for each transaction giving you the satisfaction of knowing that they were successfully processed, declined or if they returned any errors.