A non-exhaustive list of hydrophone adopters is provided below.
Talos Linux - Talos Linux is Linux designed for Kubernetes – secure, immutable, and minimal. Talos Linux is using hydrophone to run Kubernetes end-to-end tests, including certified conformance tests.
Kubermatic - Kubermatic empowers organizations worldwide to fully automate their Kubernetes and cloud native operations across multi-cloud, edge and on-prem.