Playgrounds are interactive coding environments that allow developers to write Swift code and see the results immediately without running the project. Playgrounds come bundled with Xcode 6 and support Swift for both iOS and OSX development. Playgrounds provide features like a text editor, quick look previews of values, and value history to visualize how values change over time which make them useful for learning Swift. However, playgrounds can be slow and Xcode crashes sometimes since it was still in beta when the document was written.