I have a developed a complete point of sale system that I want to start integrating credit card processing into it. I would like to know if there are SDK' package or Activex/DLL component that I can buy to process Credit Card Transactions within my application.
I know that some Merchants offer API or SDK to communicate with their systems but I would be locked into doing processing with their systems only. I am looking for somewhat universal solution tool that allows me to do processing with different CC processing gateways.
Just incase you might need to know: The system is a Windows based (VB6), Internet connectivity available.