Fleet

Fleet manages laptops, servers and phones through osquery, which means you query your fleet with SQL instead of clicking through a console. Apple, Windows, Linux, iOS, Android and ChromeOS are all covered, and the free tier includes working MDM rather than a demo.

Self-hosting is Go with MySQL and Redis. It scales to very large fleets and the documentation is unusually good, but expect a real deployment project rather than an afternoon.

Fleet Premium is $7 per host per month and moves a lot behind that line: zero-touch setup, BYOD enrollment, script execution, vulnerability scanning with EPSS and CVSS scoring, file integrity monitoring, role-based access control and audit logging. The split is fair. Visibility and inventory stay free, compliance and remediation cost money. At 500 devices Premium runs $42,000 a year, so do the arithmetic before assuming it is cheap.

The catch is the license. Fleet is MIT except the ee/ directory, which is proprietary, and the client-side JavaScript carries its own terms. Open core, not uniformly open source, and that boundary matters if you intend to modify it.