Airnode is a fully-serverless oracle node that is designed specifically for API providers to operate their own oracles. Its code base is a monorepo managed using Lerna. The Airnode monorepo has several packages. Some of these packages are used by dApp developers and API providers to interact with or to build Airnode. A few are simply used for internal Airnode development.
Airnode packages are cross platform, available as npm packages or docker containers. You should also be able to clone, build and use the packages on any platform. However there is no guarantee that the development only features (e.g. test or examples) will work out of the box. It is recommend to use UNIX based systems for development. If you are using Windows, consider WSL2.
airnode-adapter: The module that makes an API call, processes the response and returns a single value.
airnode-admin: A package/CLI tool to interact with the Airnode contracts across chains.