PracticePanther - PracticePanther offers CRM, invoicing, time tracking and communication solutions for law firms.

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

iDempiere - iDempiere Business Suite ERP/CRM/SCM done the community way.

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

PHC FX - PHC FX is a comprehensive solution that offers a wide range of functionality at any price.

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.