The most innovative online journals are maturing rapidly and distinctive new features are emerging. Foremost among these features is the hypertext link, popularised by the World Wide Web and which will form the basis of a new, highly integrated scholarly literature. Journal integration in this instance seeks to recognise, extend and exploit relationships at the level of journal content the papers while maintaining some of the familiar contexts, in some cases journal identities, that define the content hierarchy and inform decision-making by readers.
Links are a powerful tool for journal integration, most immediately in the form of citation linking.
The paper reviews examples of citation linking in practice, and describes a new system, a link service, which is being developed to support novel and flexible linking mechanisms on the Web. One application of this link service is the Open Journal project, which is working with journal publishers to investigate the most effective ways of applying these powerful link types to enhance online journals.