The Internet is a remarkable catalyst for creativity, collaboration and innovation, providing us today with amazing possibilities that just two decades ago would have been impossible to imagine. Our challenge today is to prepare a trip into the future: what will be the Internet in ten or twenty years from now and what more amazing things will it offer to people? In order to see what the future will bring, we first need to consider some important challenges that the Internet faces today. European scientists proved that they are at the forefront of Internet research already since the invention of the web. But the challenges are huge and complex and cannot be dealt with in isolation. The European Future Internet Assembly is the vehicle to a fruitful scientific dialogue, bringing together the different scientific disciplines that contribute to the Future Internet development. Until now, scientists from more than 90 research projects were funded with around 300 million euros under the 7th Framework Programme. Another 400 million euros will be made available in the near future. These amounts coupled with private investments bring the total investment to more than a billion euros, showing Europe’s commitment to address the challenges of the future Internet. This book is a peer-reviewed collection of scientific papers addressing some of the challenges ahead that will shape the Internet of the Future. The selected papers are representative of the research carried out by EU-funded projects in the field. European scientists are working hard to make the journey to the Future Internet as exciting and as fruitful as was the trip that brought us the amazing achievements of today. We invite you to read their visions and join them in their effort so Europe can fully benefit from the exciting opportunities in front of us.