Abstract
This chapter deals with digital documents used as a medium for collective practices. Documents of this kind are hyper- fragmented because they are authored at a different time (weblog) and even by different people (wiki). But these fragments are also massively linked to one another (“semantic web” in a broad sense). In the beginning of this chapter, a theoretical framework is given with the notions of document for action and annotation. Then, a state of the art is given in several domains: medical care, design in mechanics, design of open source software, scholarly documentation.