We're working on a Container Registry for https://molnett.com. We don't really want to use Harbour as we want to manage our own AuthN/AuthZ and are fully multi-tenant, so we decided to build our own on top of Distribution.

Going from Manifest to OCI is a bit tricky and performance for calculating total storage based on metadata is hard to get right. But the result is that we own our full registry implementation and can take it any direction we want. Quite happy with that!