Stripe - Online payment processing for internet businesses. Stripe is a suite of payment APIs that powers commerce for online businesses of all sizes. Use Stripe’s payment platform to accept and process payments online for easy-to-use commerce solutions.

Kajabi - Kajabi is the only Knowledge Commerce platform today with everything you need to market, sell, and deliver your knowledge online.

Chargebee - Chargebee lets you manage subscriptions and payments at scale, handle custom recurring billing scenarios, reduce subscription churn and simplify accounting.

Tendenci - Tendenci - The Open Source AMS is a cloud-based​ all-in-one management SaaS solution for Non-profits and Associations.

Killbill - Open-Source Subscription Billing and Payment Platform

YourMembership - YourMembership provides membership management software integrated with social networking features.