In early 2016 a new image manifest specification (the v2.2 schema) was finalized for the Docker Registry. One of the key benefits added in the new specification was "manifest lists": a way to combine multiple platform-specific images into a single reference (a "name:tag") in the registry. For example, a name:tag like "nginx:latest" could refer to a manifest list with three entries: one for x86_64, one for ARM, and one for POWER CPUs. When a Docker engine running on any of those platforms was asked to run "nginx:latest", the correct matching version would be pulled and run on the engine's platform. Phil will describe the new schema format and the engine support found in Docker Registry v2.3 and Docker 1.10 and above. He will also show a new tool which enables the creation of these "manifest list" entries. Phil will also demonstrate using manifest lists across several platforms.