15 Popular Payment Gateway Solutions:
1. PayU
2. PayPal Payments Pro
3. Braintree
4. Stripe Subscriptions
5. Skrill
6. Adyen
7. Amazon Payments
8. Authorize.Net
9. BlueSnap
10. CyberSource
11. CardinalCommerce
12. Payza
13. Avangate
14. Converge
15. WorldPay