OpenFaaS

OpenFaaS (Functions as a Service) is an open-source framework for building serverless functions that run on Kubernetes or Docker Swarm — deploy any container as an auto-scaling function without being locked into a cloud provider's proprietary serverless platform (AWS Lambda, etc.).

Any Docker container can become a function through OpenFaaS's watchdog process, meaning existing code in any language can be wrapped as a serverless function without a rewrite, and it scales to zero when idle like commercial FaaS platforms.

Used by teams wanting serverless deployment patterns on their own Kubernetes infrastructure, avoiding vendor lock-in to a specific cloud's Lambda-equivalent service.