# 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 - [`juju_start_unit`](https://documentation.ubuntu.com/juju/4.0/reference/resource-compute/list-of-commands-available-on-a-compute-resource-provisioned-by-juju/list-of-juju-introspect-macros/juju_start_unit.md): Start a stopped unit agent within a single Juju process using juju_start_unit introspect function on deployed machines. ## Optional - [Top-level llms.txt](https://documentation.ubuntu.com/juju/4.0/llms.txt): Complete documentation index.