Knative

Knative is a Kubernetes-based platform to build, deploy, and manage modern serverless workloads, originally developed at Google with contributions from IBM, Red Hat, VMware, and Pivotal, and now a CNCF graduated project. Knative extends Kubernetes with two core components: Knative Serving and Knative Eventing. Knative Serving provides a set of custom resources (CRDs) for deploying and managing stateless serverless applications with automatic scaling (including scale-to-zero when idle), traffic splitting for blue/green and canary deployments, progressive rollout with gradual traffic shifting, request routing with custom domains and TLS termination, revision management (immutable snapshots of code and configuration for easy rollbacks), and concurrency control with configurable target and limit values per revision. The autoscaler (KPA - Knative Pod Autoscaler) scales based on concurrent requests or requests per second, with configurable scale-to-zero grace periods. Knative Eventing provides a unified event delivery model using CloudEvents specification, with event sources (Kubernetes events, GitHub webhooks, Kafka, AWS SQS, GCP PubSub, custom sources), channels (in-memory, Kafka, NATS for event buffering), subscriptions and triggers (content-based routing via CloudEvents attributes), event sinks (services, functions, or any addressable Kubernetes resource), and the Broker/Trigger pattern for decoupled event production and consumption. As of 2026, Knative has over 5,600 stars.