The design system is a set of open source design and front-end development resources for creating Section 508 compliant, responsive, and consistent websites. It builds on the U.S. Web Design Standards and extends it to support additional CSS and React components, utility classes, and a grid framework to allow teams to quickly prototype and build accessible, responsive, production-ready websites.
It is currently being applied to HealthCare.gov. It is open source and freely available to use by anyone.