The social ecosystem. A pulsating, thriving community of very diverse, at times divisive players, all driven by a common mission: to change the world for the better. It is a potent force on the planet. And it is growing. It is organized around several million civil society groups with a presence in every country in the world. More than 20,000 of these groups operate across borders. It is equivalent in size to the world's fifth-largest country, spending more than US$1.9 trillion a year, and providing more than 4.8 million full-time equivalent jobs. To accomplish its mission, the social ecosystem employs a myriad of tools and approaches. Each player has its own, defined, but continually evolving, role toplay. There are those who need help (beneficiaries), those who help (social purpose organizations), and those who help those helping (the capacity builders). These core players depend upon the wider community, the media,and the government for support. Indeed, they can be so effective that half of the populations in some countries are mobilized to their cause. There are, of course, problems and difficulties. For as much as the social ecosystem is about change, it is also beset by the forces of change. Enter the neophilanthropists who seek to introduce market and business practices, some of which appear to be at odds with the values of the social world. And from within the sector, new heroes—the social entrepreneurs—are emerging to create social change on an unprecedented scale in new pattern-changing ways. Meanwhile, the power of technology and innovation to foment disruptive change is enabling new possibilities and outcomes. The demands of accountability placed by civil society players on corporations and governments are rebounding on them. All these factors, and more, are transformingthe social ecosystem even as it seeks to transform the larger world. The World that Changes the World sets out, for the first time, a holistic, complete, and detailed view of the fascinating social ecosystem: what it is, what it could be, and where it could be going.