This book explores the interwoven construction of gender, expertise, and information technology by starting from three positions of information systems development in Finland -- male computing pioneers' autobiographical accounts, women developers' oral histories, and an office workers' study circle with related interviews -- and, fourthly, from the codes of ethics of international computing professionals' associations ACM and IFIP. By applying Dorothy Smith's theory of conceptual practices of power, information technology is understood as textuality in which texts, e.g. programs, professional journals and electronic messages, are produced and interpreted through people's particular practices and by using particular knowledges of information technology. Both practices and knowledges are organized within materially-based social relations. Gender intertwines with information technology through social practices. Gender is studied on the level of social -- often textually mediated -- relations, in terms of gendering hierarchies and divisions of labour, but also at the level of subjectivity, in terms of definitions of information technology made by subjects. The second major aim of this work is to participate in the development of methodologies on gender and technology research. The study pays attention to persistently male tendencies of information technology but it looks for spaces available for women as well.