# Juju > Juju is an open source orchestration engine for deploying, integrating, and managing applications across Kubernetes, VMs, and bare metal using software operators called charms. 2026 CC-BY-SA, Canonical Ltd. ## Pages in this subsection - [Util suite](https://documentation.ubuntu.com/juju/4.0/contributor/reference/testing/unit-testing/util-suite.md): Leverage util suites like BaseSuite and FakeHomeSuite for structured test setup, teardown, and environment isolation in Juju. ## Optional - [Top-level llms.txt](https://documentation.ubuntu.com/juju/4.0/llms.txt): Complete documentation index.