Networked computer games, distributed virtual reality systems, and shared whiteboard presentations are prominent examples for a new class of media. Unlike audio and video streaming this media class allows a distributed group of users to interact with the medium itself. We therefore call this media class "distributed interactive media". This book investigates the distributed interactive media class in detail. It covers a broad range of topics, including an abstract media model, how to ensure consistency, an application-level protocol, and how to develop reusable functionality such as support for late-comers and session recording. The key intention of this book is to demonstrate that distinct distributed interactive media have many problems in common and to show how to solve these problems in a generic and reusable fashion for the whole media class.