Tekton
Tekton is a Kubernetes-native open-source framework to build CI/CD systems. It allows you to build, test, and deploy across multiple cloud providers or on-premises systems by abstracting away the underlying implementation details. The way Tekton works is by defining a set of tasks that are executed in a sequence. Each task is a container that runs a predefined set of commands. The power of Tekton is it's flexibility and ability to be extended or templated to fit your needs.
Tekton is at the moment the CI/CD tool that i use for most of my env. I'm searching for a way to extend it's capabilities to have more tools in my belt.