The Portuguese version of Wikipedia has existed since May 2001 and contains more than 1.7 million articles. But what, over these 25 years, has driven Wikipedia and its sister projects in Brazil? “Wikimedia in Brazil: the power and challenges of free knowledge” , launched in February by EDUFBA in partnership with Wikimedia Brasil, brings together chapters that help tell the story of the Wikimedia movement in the country, beyond inspiring new contributions and reinterpretations to expand and improve the content available in the free knowledge ecosystem. The idea arose in 2023, when Wikimedia Brasil (then Wiki Movimento Brasil) celebrated its 10th anniversary. The book aims to record and reflect on the work of the volunteers who build Wikimedia, gathering accounts that document the trajectory of people and activities that are central to the development of Wikimedia in Brazil.…