> ## Documentation Index > Fetch the complete documentation index at: https://docs.preloop.dev/llms.txt > Use this file to discover all available pages before exploring further. # Introduction > What Preloop runs, and whether you need the self-hosted control plane or the standalone runner. Preloop runs GitHub Actions workflows on hardware-isolated microVMs. Your `.github/workflows` files stay unchanged. You choose where the jobs run: on your own machine, on servers you operate, or on hosts that register with GitHub. Preloop ships as two products. You can use either one on its own. A failed step, a fix in another pane, and a re-run, all local with no push required Run unmodified workflows locally or on your own infrastructure. `preloop run` executes a workflow against your working tree, including uncommitted files. `preloop serve` runs the engine, which can start runs from GitHub pushes and pull requests through a GitHub App, and can pause a failed job so you can debug it. A standalone, drop-in replacement for `actions/runner`. It registers with GitHub or a Preloop server, polls for jobs, and runs them on the host where it is installed. It needs no control plane, microVMs, or background services. Preloop system overview: clients, the control plane, the VM pool, and microVMs ## Where to go next Install the CLI and run your first workflow locally. Requirements for macOS, Linux, and WSL2, and running the engine as a service. The config file, GitHub credentials, and secrets. Every command and flag. How closely Preloop matches GitHub Actions, and where it differs. How Preloop compares with other local and self-hosted CI tools. This documentation is built and hosted on [Mintlify](https://mintlify.com), a developer documentation platform.