Ultimate Guide to Drupal 9

On June 3, 2020 Drupal 9 was released, representing an important next step in the evolution of Drupal by building upon what already exists in Drupal 8 and laying the foundation for the future.
But as Dries Buytaert, Drupal founder and project lead, says: "The big deal about Drupal 9 is...that it shouldn't be a big deal."
Among other enhancements, the December 2 release of the Drupal 9.1 minor release provided improvements to the experimental administration theme, Claro, and introduced the experimental front-end theme, Olivero, which focuses on greater accessibility.
Acquia, as a committed member of the Drupal community and foremost expert on Drupal 9, is publishing the Ultimate Guide to Drupal 9 to help you get up to speed on what's new and prepare your website for an upgrade.
Download your copy of the Ultimate Guide to Drupal 9 today.
Revised and updated for Drupal 9.1 as of December 2020.