Pattern Lab is a collection of tools to help create and maintain atomic web design systems.
All matter, no matter how complex, can be broken down into molecules which can be broken down further into atomic elements. All web interfaces can be broken down down the same way. Atomic Design provides a methodology for building an effective design system. It consists of five distint stages: atoms, molecules, organisms, templates and pages.
More documentation coming very soon. In the meantime, check out these notes.