Killbill - Open-Source Subscription Billing and Payment Platform
Subscription Billing - Sales Order Processing that automates and manages cyclical and subscription based billings by generating invoices, quotes or orders in Dynamics GP.
Recurring Payments - No need to create invoices. No need to remind clients to pay
Trexle - Payment Platform Supporting One-time and Recurring Billing
TillyPay - Recurring & single payment links, powered by Stripe.
SAP ERP - SAP ERP is enterprise resource planning software developed by the German company SAP SE.