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Best / Serverless functions

Best open-source Serverless functions

The best self-hosted functions split in the c17.io catalog is Fission for Kubernetes functions (the published Workers/Lambda stack), Knative Serving for scale-to-zero, Spin for Wasm/Workers-shaped isolates, and wasmCloud as the CNCF Wasm host. OpenFaaS CE is not ranked: the repo LICENSE requires a commercial EULA for commercial use of CE. A git-push PaaS stays on /best/self-hosted-paas.

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Ranked picks

  1. 1

    Fission

    Apache-2.0 serverless functions on Kubernetes — the c17 Cloudflare Workers / AWS Lambda path.

    When to pick it: Functions on a cluster you already run.

    8,936 stars in the catalog

  2. 2

    Knative Serving

    Apache-2.0 scale-to-zero request-driven compute (Knative Serving).

    When to pick it: Serving that can sleep, on Kubernetes.

    6,110 stars in the catalog

  3. 3

    Spin

    Apache-2.0 Wasm serverless (spinframework/spin) — the Workers-shaped isolate path.

    When to pick it: Wasm functions, not a Kubernetes function framework.

    6,537 stars in the catalog

  4. 4

    wasmCloud

    Apache-2.0 CNCF Wasm host for polyglot apps across cloud, Kubernetes, or edge.

    When to pick it: A Wasm lattice, not a single FaaS CLI.

    2,459 stars in the catalog

How they compare

ToolLicenseSelf-hostBest for
FissionApache License 2.0MediumFunctions on a cluster you already run.
Knative ServingApache License 2.0MediumServing that can sleep, on Kubernetes.
SpinApache License 2.0MediumWasm functions, not a Kubernetes function framework.
wasmCloudApache License 2.0MediumA Wasm lattice, not a single FaaS CLI.

Related pages

FAQ

Workers or Lambda?
Same published stack — /replace/cloudflare-workers and /replace/aws-lambda. Spin if you want Wasm. Fission/Knative if you want Kubernetes.
Why not OpenFaaS?
OpenFaaS Ltd contributions are under a Community Edition EULA for commercial use. This ranking uses Apache-2.0 runtimes.
Is this Coolify?
Coolify is git-push PaaS — /best/self-hosted-paas. This page is functions.
Are these free?
Fission, Knative Serving, Spin, and wasmCloud are Apache-2.0. You pay the cluster. Template users never pay c17.
How do I deploy it?
Open /stacks/fission-functions. A single Railway service is often the wrong size — a cluster or a VPS is the honest path.

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