Killbill

Judgement

What it is

Building block

What it does

A subscription billing and payments platform covering catalogs, subscriptions, usage, invoicing, payment gateways, credits, tax and dunning.

Adopt it when

A company with Java engineers needs mature subscription billing it fully controls, at scale.

Watch out

Complex to set up and customise, and the plugin ecosystem needs Java skills.

Ready for

Production-ready

Runs as

Self-hosted server

Built with

Java, MySQL and PostgreSQL

How established

Established: started 14 years ago, latest release killbill-0.24.22.

What the license allows

You can build it into a product you sell, as long as you keep its copyright notice.

Judged on 2026-11-03 from the project's README and GitHub data. The license and age lines are worked out directly.

Built from

Follow it down: Killbill → JDK → LLVM project → runs on a microchip

How compilers were built, back to punched paper tape

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