Book excerpt: Today, "social entrepreneurship" describes a host of new initiatives, and often refers to approaches that are breaking from traditional philanthropic and charitable organizational behavior. Nowhere is this more true than in the United States—where, from 1995–2005, the number of non-profit organizations registered with the IRS grew by 53%. But, what types of change have these social entrepreneurial efforts brought to the world of civil society and philanthropy? What works in today's environment? And, what barriers are these new efforts breaking down as they endeavor to make the world a better place? The Real Problem Solvers brings together leading entrepreneurs, funders, investors, thinkers, and champions in the field to answer these questions from their own, first-person perspectives. Contributors include marquee figures, such as Nobel Laureate Muhammad Yunus, Ashoka Founder Bill Drayton, Jacqueline Novogratz, Founder of the Acumen Fund, and Sally Osberg, CEO of the Skoll Foundation. The core chapters are anchored by an introduction, a conclusion, and question-and-answers sections that weave together the voices of various contributors. In no other book are so many leaders presented side-by-side. Therefore, this is the ideal accessible and personal introduction for students of and newcomers to social entrepreneurship.