Maestro provides a declarative approach to building production-grade Kubernetes Operators covering the entire application lifecycle.
Multicluster-controller is a Go library for building Kubernetes controllers that need to watch resources in multiple clusters. It uses the best parts of controller-runtime (the library powering kubebuilder and now operator-sdk) and replaces its API (the manager, controller, reconcile, and handler packages) to support multicluster operations.
Kubebuilder is a framework for building Kubernetes APIs using custom resource definitions (CRDs).
Soletta Project is an open source framework for making IoT applications. The project provides libraries to make it quick and easy to write software for devices.