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.
Plasso.com - Payments made simple. Sell subscriptions & products online.
Chargebee - Chargebee lets you manage subscriptions and payments at scale, handle custom recurring billing scenarios, reduce subscription churn and simplify accounting.
Killbill - Open-Source Subscription Billing and Payment Platform
Stripe Billing - A set of tools for billing and subscriptions
Marcus by Goldman Sachs - Personal loans to help manage high-interest credit card debt