Muni-Link - Cloud-based utility billing software
Lago Billing - Open-source alternative to Stripe Billing and Chargebee
Trexle - Payment Platform Supporting One-time and Recurring Billing
Metronome - Metronome helps software companies launch, iterate, and scale their usage-based business models, with billing infrastructure that works at any size and stage.
ShipForce - | Flat Rate Fulfillment
Chargebee - Chargebee lets you manage subscriptions and payments at scale, handle custom recurring billing scenarios, reduce subscription churn and simplify accounting.