One question people frequently ask is whether Drupal is WAI compatible?
Well the question itself is not quite correct. Drupal is just a framework and no one writes any code to always keep it WAI compatible.
You have to “Do Extra Work” to make any website, whether based on Drupal or any open source framework or developed from scratch, to be WAI compatible.
Answer is YES.
Complex part is getting it done, which involves a lot of extra work.