Open payment gateway libraries for Java, Python, Ruby, Node.JS, and PHP

You can checkout J2pay its clean and its supported gateway list is continuously increasing.

There's a python port of ActiveMerchant called OpenMerch, which looks quite similar to the ActiveMerchant code.

What I have seen done is just wrapping Active Merchant into a light weight web service which exposes a rest API that any of your languages can talk to. This was for a larger company that could properly lock down their networks though, so DYODD.

I created Paython: https://github.com/abunsen/Paython

Supports a few different processors:

1. Stripe
2. Authorize.net
3. First Data / Linkpoint
4. Innovative Gateway (from intuit)
5. Plugnpay
6. Samurai