This issue looks in depth at the multiplicity of the social and cultural impacts of Wikipedia. The articles analyse issues including its development and the consequences for the commercial sector and the public image of large corporations (in the article by Marcia W. DiStaso and Marcus Messner) or its role in the diffusion of culture and architectural heritage (in the article by Emilio José Rodriguez et al.). The article by Antoni Oliver and Salvador Climent details the use of Wikipedia as a structured knowledge corpus, in the framework of the state of the art in natural language processing research. In turn, the article by David Gómez proposes the concept of wikimediasphere and shows how Wikipedia actually forms part of a very dense ecosystem of projects that, though they share common elements, act with a high level of autonomy as nodes on a wider network. Lastly, the article by Nathaniel Tkacz analyses the practical and epistemological implications of one of the basic pillars of Wikipedia's core content policy - the Neutral Point of View - and its relation to a specific concept of truth.