If you rely on a screen reader or other assistive technology, you will be glad to know that Drupal has built to encourage and support the proper use of semantic markup. It has committed to ensuring that all features of Drupal core conform to the World Wide Web Consortium (W3C) guidelines: WCAG 2.0 and ATAG 2.0. Its accessibility team works to identify barriers and to resolve them. Hence, Drupal 7 and later has added some additional support for Rich Internet Applications by adding some WAI-ARIA support. There have been many improvements to both the visitor and administrator sides of Drupal, especially:
• Search engine form and presentation
• Drag and Drop functionality
• Color contrast and intensity
• Adding skip navigation to core themes
• Image handling
• Form labelling
• Removing duplicate or null tags.