This report helps funders learn about the different phases of collaboration and online tools that can help them advance all types of sharing, coordination, and cooperation. The research included an extensive literature review on collaboration in philanthropy, detailed analyses of trends from a Foundation Center survey of the largest U.S. foundations, interviews with 37 leading philanthropy professionals and technology experts, and a review of more than 170 online tools. A companion “interactive tool finder” aids the search for technology solutions.