This early access version of Getting Started with Spark Photon has been written as the Photon is about to become available, and, so, much of the content is based on the Photon’s predecessor the Core, even though the focus of the book is the Photon. The team at Spark have been extremely helpful, sharing information about the minor dierencesbetween the Photon and the Core, so that the book anticipates these dierences.