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, Drupal 9 provided improvements to the experimental administration theme, Claro, and introduced the experimental front-end theme, Olivero, which focuses on greater accessibility.
