MAVLink Protocol
MAVLink is the message-level interoperability standard for drones, and the Dronecode Foundation publishes it. The contract is the dialect XML — 19 files including common.xml, standard.xml, minimal.xml and development.xml — from which every language binding is generated, plus five JSON Schemas defining how a component describes its own parameters, actuators and peripherals. The dialect XML carries a machine-readable deprecation element with `since` and `replaced_by`.