The document discusses HTML5 and its integration with Drupal. It introduces HTML5 features like audio, video, canvas, forms, semantic markup tags. It notes that making existing Drupal templates HTML5 compliant can be easy, but that Drupal core would need significant changes to fully support HTML5, such as reworking how it generates markup. It urges the Drupal community to start work on these changes now to support HTML5 properly in Drupal 8.