Accessibility Developer Tools (ADT)

The Accessibility Developer Tools (ADT) library provides a suite of accessibility-related testing and utility code primarily for web browsers. Its core functionality includes an accessibility audit API, offering a collection of rules to check for common accessibility problems within an HTML page. Beyond auditing, it offers utilities such as contrast ratio calculation, ARIA attribute validation, and accessible name computation following WAI-ARIA specifications. The current stable version is 2.12.0, with a release cadence that appears somewhat irregular, often driven by bug fixes, performance enhancements, and new audit rules. Key differentiators include its focus on practical, rule-based audits for web content and its integration capabilities with testing frameworks like Selenium and headless browsers like PhantomJS. It's often used in CI/CD pipelines to automate accessibility checks.