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

Sellbery - Easily automate product feeds from Shopify, Magento to Amazon, eBay and other marketplaces. Fully utilize the most profitable eCommerce channels and increase sales.

Recurly - Subscription billing and recurring billing management. Recurly offers enterprise-class subscription billing for thousands of companies worldwide.

Radial - Radial offers order management and store fulfillment solutions.

Zuora - Zuora creates cloud-based software on a subscription basis that enables any company in any industry to successfully launch, manage, and transform into a subscription business.

eBay Enterprise - eBay Enterprise provides a variety of marketing, customer care, payment processing, fulfillment, fraud detection services.