Educators have just started to use wikis and most of the educational research to date has focused primarily on the use of local wikis with access limitations. There seems to be little research related to how students can contribute in global, transparent wiki communities such as "Wikipedia" and "Wikibooks". The purpose of this article is to argue that we need to extend our understanding of transparency as a pedagogical concept if we want to use these open, global wiki communities in an educational setting. By describing one wiki based course in detail, I argue that these kinds of radically transparent learning environments in tertiary education challenge traditional pedagogy and our ordinary perceptions of what a class and working assignment is. The course data in this article include a course description and teacher and student reflections on assessed group projects which produced "student written, collaboratively edited textbooks" on "Wikibooks". Student perceptions indicate positive attitudes towards global learning environments, if the didactical design is carefully planned. In the article I suggest that "outsiders" and "former and future students" should be included as categories in a pedagogical definition of transparency. These categories represent a radical expansion of course space and course availability. (Contains 1 table.)