The components are usually for iOS (though sometimes they’re for OS X), and are invariably GUI controls or views of some kind. I’ve designed literally dozens of component APIs over the years, including for clients like Apple, and I’ve learned quite a bit about the process. I periodically release open source components too, and the feedback I’ve had has helped me put together a set of guidelines for API design that I’d like to share with you. This is an important topic, whether you’re an open source contributor, or working as part of a team on a large app, or just creating your own software. 6 Reasons Why APIs Are Reshaping Your Business.