It is our great pleasure to welcome you to the 18th International ACM Conference on Hypertext and Hypermedia 'Hypertext, The Web, and Beyond: Five Autonomous Programmes, One Unified Conference'. The conference takes place in the Manchester Museum in Manchester, UK. The museum is located within the University of Manchester campus in the centre of Manchester. The city also has a rich scientific and academic heritage, with The University of Manchester being the home to twenty Nobel Prize winners and of such academic achievements as the world's first stored programmable computer, the splitting of the atom and the world's largest steerable radio telescope. This year we had a major increase in submissions on 2006, over both full technical papers, and posters and demonstrations. With submissions coming from over thirty countries across four continents from Belgium to Brazil, Italy to India, and South Korea to Sweden. With an acceptance rate of 35% the quality of the conference is maintained but with submissions such as 'Towards Better Understanding of Folksonomic Patterns', 'Revealing the Hidden Ethnography of User Browsing Behavior', and 'Assembly Lines: Web Generators as Hypertexts' our submission topics are significantly broadening. These changes are also echoed in our Keynote, After Dinner Keynote, and Closing Plenary. Our Keynote is Professor Carole Goble, Director of the myGrid project (the largest UK e-Science pilot project), producer of the widely-used Taverna open source application (now part of the Open Middleware Infrastructure Institute). She is also the co-director of the e-Science North West regional centre. Our after dinner Keynote is Professor Wendy Hall, Head of School at the University of Southampton's School of Electronics and Computer Science. She is the founding Head of the Intelligence, Agents, Multimedia (IAM) research group and has published over 350 academic papers. In 2003 Wendy was appointed President of the British Computer Society (BCS) and is one of the few females to hold a fellowship of the Royal Academy of Engineering as well as being made a Commander of The Most Excellent Order of the British Empire (CBE), awarded in 2000. Finally, we all know our Closing Plenary speaker Theodor Holm Nelson, credited with first use of the words hypermedia, transclusion, founder of Project Xanadu; here we also see his new work on CosmicBook, and understand his ideas for the future. ACM Hypertext, as a conference series, has always maintained very high quality standards, combined with a fairly strict adherence to the research topic of Hypertext and Hypermedia. Not giving in to the "hypertext and the Web are just the same" hype has allowed the conference to maintain its high profile, albeit at the expense of submission and attendance numbers. Not wishing to compromise on quality ACM Hypertext has taken a turn for broadening its scope. This has resulted in the five "autonomous programmes" of ACM Hypertext 2007. Hypertext is everywhere, in theory research, in very practical applications, in society, in personal interfaces and in culture and communication. Separate program committees evaluated submissions in each of these tracks, resulting in a selection of high quality full and short papers that offer the conference attendees a varied but in depth view of current hypertext research. Throughout the history of the ACM Hypertext Conference, researchers have tried to capture what hypertext really is. The Hypertext Models and Theory programme specifically targets this "hard core" formal study of structural, sculptural, spatial, open, dynamic and adaptive or any other type of hypertext (or Web-based Information System). The Models and Theory track has indeed attracted some visionary submissions that shape the future of WIS and hypertext systems and thus will become standard reference material in the future. Hypertext is alive and in use in various applications. The Practical Hypertext programme looked at collecting some of these applications of hypertext including The Web, Semantic Web, Web Engineering, and Web Design. These topics concern themselves with all aspects of making valuable everyday hypertext applications, not exclusively on the Web. As a result, the track has gathered a variety of papers which illustrate classical issues in practical hypertext, such as reverse linking, interesting hyperspace applications such as hyperspeech, user-assisted similarity estimation on the web, and lessons learnt from industrial semantic web applications and learning style applications. The inclusion of "Social Hypertext" this year as an explicit theme of the conference reflects the fact that this area has reached maturity. What is Social Hypertext? We might define it as Hypertext that gets better the more people use it - but Tim Berners-Lee would be the first to point out that this is exactly what the Web is. This year we made a specific effort to recruit committee members and reviewers from emerging research communities involved in technologies such as wikis and blogging and we circulated the Call for Papers within these communities. The predominant research issue that was most evident in the excellent set of papers we reviewed was that of analysis of the patterns of use of social software sites, but the area continues to evolve, and the committee's selection of papers reflects the width of the area. We hope to see this theme expand further in the future. The focus of Hypertext and the Person is on a human centered Web, with an eye towards enabling all users, including those with disabilities to benefit from hypertext and hypermedia. Usability and accessibility are stressed, with a diverse set of issues explored. Papers in this track address hypertext navigation, adaptations for individual needs, educational applications, and collaborative hypermedia. When the first ACM Hypertext Workshop convened twenty years ago, most researchers believed that the chief obstacles to widespread use of hypertext were technical and economic. Could systems perform sufficiently quickly? Could link integrity be achieved? Could society conceivably afford the cost of a digital library? At the same time, we assumed that, once the systems were designed and built, actually writing hypertexts would be a straightforward task. Today, the most daunting engineering challenges have been met, although new challenges always arise. However, the craft of hypertext writing poses many unexpected challenges. The study of hypertext fiction is a staple of university curricula throughout the world, but it is clear that we are only beginning to understand the theory of hypertext rhetoric and the practice of hypertext criticism. From the details of semantic metadata to the grand vistas of the curation of digital artifacts, and from the workaday world of microformats and weblog networks to the abstract realms of metafiction, sculptural, and feral hypertext, hypertext's impact on culture is as undeniable as it is, still, incompletely understood.