This document discusses WAI-ARIA and its role in improving web accessibility. WAI-ARIA (Accessible Rich Internet Applications) is a W3C specification that allows adding role, state and other metadata to web content to make dynamic content and interactive elements more accessible to assistive technologies like screen readers. It serves as an important "bolt on" approach to accessibility, allowing web languages like HTML and SVG to be more accessible even as they evolve beyond their original use cases.