"The CEU Democracy Institute's Center for Media, Data and Society (CMDS) embarked in November 2020 on a one-year project aimed at mapping and analyzing the work of the world's fact-checking groups, with a focus on their challenges, needs and successes. The project started with a survey of 30 fact-checking organizations worldwide, which were asked to indicate the importance of certain impact-related challenges. Based on the survey's results and research, CMDS identified four areas of interest, and also groups that have been successful in addressing these challenges. These fact-checking organizations, some of them lesser-known groups established in the past few years, and their modus operandi have been showcased in four articles covering audience outreach, methods to tackle misinformation on social media, fact-checking misinformation about the Covid-19 pandemic and fact-checking for teenagers, which were published over the course of the past year. This booklet collects all these papers in one place, presenting the results of the survey and the articles produced as part of the project, as well as an additional, fifth piece that looks into the future of fact-checking." (Introduction)