Islandora CLAW is the project name for development of Islandora to work with Fedora 4 and Drupal 8, formerly known as Islandora 7.x-2.x. The existing version of Islandora, 7.x-1.x works as a bridge between Drupal 7.x and Fedora 3. Islandora CLAW does more than simply replace that base layer with Fedora 4. It is a total re-architecting of the interaction between the various pieces.
This new structure has several advantages:
Parcelling out the various services and dependencies allows for more horizontal scalability;
Changing the relationship between Drupal and Fedora allows for a more flexible approach to front-end management (i.e, it need not be Drupal) while also taking much greater advantage of features available from Drupal (i.e, Fedora objects are treated more like nodes, for the purposes of using Drupal contrib modules. Many Islandora 7.x-1.x modules are redundant in Islandora CLAW because they reproduce existing Drupal contrib modules that can be used out of the box in Islandora CLAW);
Native RDF functionality in both Drupal and Fedora, allowing an Isladora CLAW installation to be both on the web, and of the web;