From Deep Sky Technologies:
eTrans is a 4th Dimension component which provides a simple, consistent interface to online credit card authorization service providers. Using eTrans, 4th Dimension developers can build credit card authorization services into their 4D databases in a matter of minutes. With eTrans, credit card and electronic check processing can be added to 4D applications with as little as four (4) lines of code. Switching between gateway processors requires a change in only a single line of code when using the eTrans component. This is ideal for vertical market applications where the processing of credit cards and electronic checks would be a value added feature for end customers.