Payment gateway integration is crucial for sites that have ordering or shopping cart functionality. Payment gateways all have a common goal, to allow for credit card, bank transfer or e-check payments. 
Inguza Technology AB has so far integrated the following payment gateways in commercial systems:
- AuthorizeNet AIM
- AuthorizeNet AIM Refund API
- AuthorizeNet ARB (not recommended as it is very inflexible)
- AuthorizeNet CIM
- AuthorizeNet CIM Refund API
- AuthorizeNet SIM
- Clickbank INS
- Paypal Website Payments Standard
- Paypal Subscriptions and Recurring Payments
- Paypal IPN
- Paypal INS
- Paypal Refund API
- RBS WorldPay Futurepay
- RBS WorldPay Direct Junior
- RBS WorldPay XML Direct and 3-D Secure
- RBS WorldPay XML Direct with Futurepay
- RBS WorldPay XML Refund API
- Stripe
- Litle & Co
Each payment gateway have its own advantages but also drawbacks.