Authoring of adaptive and adaptable hypermedia : an introduction

This opening paper introduces the special issue on 'Authoring of adaptive and adaptable hypermedia', which is based on selected, invited and revised papers from a workshop series on the same topic, as well as on an open call. We hope that this selection can give the reader a feeling about current hot topics and unsolved problems in this field, on one hand, and about the current state-of the art, on the other. Long considered secondary to the research into adaptive hypermedia, the authoring of such systems brings its own issues, particularities, and new exciting problems for the world of research at large to try and tackle. For educational practitioners, this selection gives them some insight into the direction educational systems can and might be moving, and a more clear idea of what to expect from technology