The desired outcome of all scientific endeavour is to advance the the body of accumulated knowledge
in a materially verifiable way. This knowledge is communicated through the research literature, which
presents scientific claims and their justifications through forms of discourse, expressed in document
genres legitimated by a given research community. The study of the rhetorical and argumentative
characteristics of such discourse has long-standing traditions, the results of which also provide insights
into how scientific publishing, search and debate might take new forms on the social-semantic web.
This article surveys, for a general readership, the growing body of work that models scientific
discourse for social-semantic web applications, and offers a framework highlighting key features to
help compare the various models. Secondly, we present examples of tools based on discourse models,
which facilitate semantic navigation, structured debate, human and machine annotation of scientific
texts, and literature analysis/alerting services. Finally, we identify some of the open research
challenges confronting the field, and summarise the ways in which they are being tackled.