There is a lot of new ground to cover in Drupal 8, especially for developers. For those of you who are already familiar with developing in Drupal 7, these free Drupal 8 Activity Cards will help you with the leap. The cards were created by Tanay Sai and his study group while they bootstrapped themselves on the new code. They’ve done an awesome job covering the main topics you’ll need to know for the switch from Drupal 7 to 8. Each card is a lesson on a new development topic and altogether they cover 21 days of lessons.