Apiman is an open-source API management platform that describes itself as extensible. It governs APIs at runtime through policies, for example throttling and quotas, centralised authentication and IP filtering, and metrics for billing or usage insight. The same API can be offered through several plans with different service levels. Apiman consists of a REST API, the Apiman Manager interface with multi-tenancy, permissions and approvals, and a standalone developer portal. You build custom policies with Java plugins. Apiman is software that you run yourself, on bare metal (including air-gapped) or in the cloud.
Apiman was started by Red Hat, which is no longer directly involved; the community maintains the project and Black Parrot Labs offers paid enterprise support. The software is licensed under the Apache License 2.0 and, according to the project, has no paywalled features. Because you host Apiman yourself, you decide where gateways, manager and data reside, including within the EU.