GPlatform Billing
The commercial half. It owns money, and deliberately owns nothing else.
Accounts, the price catalogue, the Stripe relationship, subscriptions, dunning and usage-based charging, for every product in the family. It never decides what a customer is entitled to: that stays in GPlatform Control, and this side asks.
GPlatform Billing is built and maintained by Gelhaus Solutions. The detail — what it does, how it is built and where it stands — is on their site.