Augmenting the Web through Open Hypermedia The Development of the Arakne Environment, a Collaborative Open Hypermedia System for Web Augmentation Niels Olof Bouvin Ph.D. Thesis University of Aarhus November 2000 2 Contents 1 Foreword 7 1.1 Structure of this Thesis . 7 1.2 Papers . 8 1.3 The Arakne Environment . 9 1.4 My Background . 9 1.5 Acknowledgements . 10 2 Danish Summary 11 3 Introduction and Motivation 13 3.1 Working on the Web . 13 3.2 Lies Open Hypermedia Dead in the Wake of the Web? . 14 3.3 The Vision of the Augmented Web . 15 3.4 Open Hypermedia Web Augmentation Tool: A Definition . 16 4 Hypermedia and the Web 17 4.1 A Brief History of Hypermedia . 17 4.2 The Classical Monolithic Hypermedia Systems . 17 4.3 Open Hypermedia . 19 4.3.1 Sun’s Link Service . 20 4.3.2 Microcosm . 21 4.3.3 Devise Hypermedia . 22 4.3.4 HyperDisco . 23 4.3.5 HOSS . 24 4.3.6 Chimera . 25 4.3.7 Construct . 25 4.3.8 Integrating Third-party Applications . 26 4.3.9 Open Hypermedia on the Web . 27 4.4 Hypermedia Standardisation Efforts . 29 4.4.1 The Dexter Hypertext Reference Model . 30 4.4.2 Open Hypermedia Systems Working Group . 31 4.5 CSCW and Collaborative Hypermedia . 32 4.6 Hypermedia: Concluding Remarks . 35 4.7 A Brief History of the Web . 35 4.7.1 Hyper-G . 36 4.7.2 The Semantic Web? . 37 4.7.3 Collaboration on the Web . 38 4.7.4 WebDAV . 39 3 4 CONTENTS 4.8 WWW, or What is Wrong with the Web? . 39 4.9 Summary . 41 5 Related Work 43 5.1 XLink . 43 5.2 Internet Explorer Add-ons . 44 5.2.1 Flyswat . 45 5.2.2 iMarkup . 46 5.2.3 Third Voice . 46 5.3 Summary . 46 6 Contributions 47 6.1 [P1]: Unifying Strategies for Web Augmentation . 47 6.2 [P2]: Opening Temporal Media for Web Augmentation . 48 6.3 [P3]: The Arakne Environment and the future of OHSWG . 49 6.4 [P4]: The Collaborative Arakne Environment . 52 6.5 [P5]: The iScent Framework . 52 6.6 Prototypes . 55 6.6.1 DHM/WWW . 55 6.6.2 Navette . 56 6.6.3 The Arakne Environment . 56 6.7 Summary . 60 7 Challenges for Web Augmentation 61 7.1 Working with Web Browsers . 61 7.1.1 The Ideal Web Browser . 63 7.2 Experiences with Java . 64 7.3 Hypermedia Scalability . 65 7.3.1 Scalability through Interchange Files . 66 7.4 Summary . 67 8 Conclusion 69 8.1 Primary Results . 69 8.2 Web Augmentation in the Future? . 70 8.2.1 Commercial future of Web augmentation . 71 8.3 Future Work . 72 8.3.1 Collaboration in the Arakne Environment . 72 8.3.2 Open Sourcing the Arakne Environment . 72 A Use Studies 75 A.1 Landbrugets Rådgivningscenter . 75 A.1.1 The Information Series . 77 A.1.2 Assembling a publication . 77 A.1.3 Handling law material . 77 A.1.4 Moving from paper to the Web . 78 A.1.5 Work with Landbrugets Rådgivningscenter . 78 A.1.6 Experiments at Landbrugets Rådgivningscenter . 80 A.2 Guided Tours at Opasia . 80 CONTENTS 5 B Installing the Arakne Environment 83 B.1 Systems Requirements . 83 B.2 Installing JIntegra . 83 B.3 Installing the Arakne Environment . 83 B.4 Starting the Construct Servers . 84 B.5 Starting the Arakne Environment . 84 C Vocabulary 85 Bibliography 87 List of Figures 4.1 The Construct Process Architecture (from [52]) . 26 4.2 The General Dexter Architecture (from [62]) . 30 4.3 The OHSWG Navigational Data Model . 32 4.4 The Uniform Resource Locator . 36 4.5 The General Web Architecture . 37 5.1 The iMarkup Application (from http://www.imarkup.com/) . 45 6.1 The Arakne Framework . 47 6.2 Mimicry playing the endpoint ’Endpoint 14’ . 49 6.3 The Arakne Environment with Mimicry . 50 6.4 The iScent Framework . 54 6.5 The DHM/WWW Prototype . 55 6.6 The Navette Prototype . 57 6.7 Early Arakne Version . 58 6.8 The Arakne Environment: Two sessions, two views, and a Session Manager. The ticker tape is visible at the bottom. The tabbed panes just above the ticker tape is used to switch between joined sessions. 59 A.1 The Organisation of Danish Agricultural Advisory Services . 75 A.2 Guided Tour at Opasia . 81 List of Tables 4.1 Components and entities in the Dexter model . 31 6 Chapter 1 Foreword 1.1 Structure of this Thesis This report forms the first part of of my Ph.D. thesis titled “Augmenting the Web through Open Hypermedia”. This part summarises my work and relate it to the hyper- media and Web research fields. The second part is formed by the five papers described below in Section 1.2, all dealing with augmenting the Web with open hypermedia or collaboration. The third and final part of my Ph.D. is the Arakne Environment, a sys- tem for creating open hypermedia structures on top of Web pages, which availability is described in Appendix B. It is also available on the CD delivered with this text. Foreword This chapter Danish Summary A summary of the thesis in Danish. Introduction and Motivation The Web is briefly introduced, along with some sce- narios, highlighting some shortcomings of the Web. These scenarios are used to introduce the term ’Web augmentation’, that is using open hypermedia technol- ogy to structure the Web. Hypermedia and the Web My work is related to both open hypermedia research and the Web community. This chapter gives an overview of both fields as well as a brief introduction to the relevant CSCW topics, with special focus on the areas directly related to my work. Related work There are a growing number of commercial products aimed at Web augmentation. This chapter introduces some of these systems along with a de- scription of XLink, a W3C XML standard for navigational hypermedia. Contributions My contributions to the field based on the papers described in Sec- tion 1.2. I have mainly worked directly on Web augmentation and this is re- flected in the papers. My experiences with the Open Hypermedia Systems Work- ing Group compliant Construct servers are reported, as is work on extending and generalising the approach to shared awareness found in the Arakne Environment. Challenges for Web Augmentation While Web augmentation is greatly eased by the accessibility of Web standards, there are some lessons with Web browsers and Java accumulated through my work, that identifies some of the obstacles remain- ing. 7 8 CHAPTER 1. FOREWORD Conclusion This chapter summaries the results, I have achieved, and sets the direc- tions of my future work. The Arakne Environment and its related technologies have now reached a point where work can begin in earnest. Use studies Two cases, one detailing the need for Web augmentation at Landbrugets Rådgivningscenter, another showing Web augmentation in the form of guided tours used in practice at the Opasia Web portal (the largest Danish ISP). Installing the Arakne Environment A short description detailing how to download and install the Arakne Environment. Vocabulary Short definitions of various terms used throughout this text. 1.2 Papers The core part of this thesis consists of the following papers, included with the thesis: • N. O. Bouvin. Unifying strategies for Web augmentation. In Proceedings of the 10th ACM Hypertext Conference, pages 91–100, Darmstadt, Germany, Feb. 1999. This paper introduces the term “Web augmentation”. Based on a study of a number of Web augmentation tools, a general framework to model Web augmentation, as well as an implementation using this framework is presented. Referred to in this text as [17] and then marked with [P1]. • N. O. Bouvin and R. Schade. Integrating temporal media and open hypermedia on the World Wide Web. In Computer Networks — The International Journal of Computer and Telecommunications Networking, (31):1453–1465, 1999. Tradi- tionally, Web augmentation has concentrated on adding links to Web pages, that is, HTML documents. This paper describes how temporal media, such as video or audio clips, may be augmented with links on the Web. Referred to in this text as [20] and then marked with [P2]. • N. O. Bouvin. Experiences with OHP and issues for the future. in Lecture Notes in Computer Science 1903. Springer, 2000. Based on the work of porting the Arakne Environment to the Open Hypermedia Protocol, this paper reflects on the state of the standards developed by the Open Hypermedia Systems Working Group, and discusses how this work can continue in the future. Referred to in this text as [19] and then marked with [P3]. • N. O. Bouvin. Collaborative Web-based open hypermedia and mutual awareness. To be submitted for publication. This paper describes how collaborative work and shared awareness is supported in the Arakne Environment, with special focus on how collaboration can be seamlessly integrated into the interaction with the system. Referred to in this text as [15] and then marked with [P4]. • K. M. Anderson and N. O. Bouvin. Enabling project awareness and intersub- jectivity via hypermedia-enabled event trails. Submitted for publication. This paper introduces the iScent architecture, a system to support shared awareness and intersubjectivity between co-workers. As such it is a continuation and gen- eralisation of the awareness tools already present in the Arakne Environment. Referred to in this text as [6] and then marked with [P5]. 1.3. THE ARAKNE ENVIRONMENT 9 1.3 The Arakne Environment The Arakne Environment is a tangible result of my Ph.D.