Webometrics, the quantitative study of Web phenomena, encompasses a variety of types of research, some of which date back to the early years of the Web although the widespread adoption of the term itself is relatively new. The dynamic, diversified, and far-reaching nature of the Web provides a fertile ground for knowledge discovery. Frequencies and patterns of word and phrase usage on Web pages can provide valuable information for search algorithms. The selective coverage of Web sites by search engines reflects favor toward certain communities and bias against others. Use of query terms reflects issues of interest and concern to people. The size and structure of Web sites around the world can provide extensive social, cultural, economic, and political information. Web links, although individually less reliable sources of information than bibliographic citations, may reveal significant trends when aggregated over large areas of the Web. This issue will provide a forum for a broad spectrum of scholars to compile a body of research that begins to cement these emerging areas into a coherent field. It will also serve as a tribute to Tomas Almind who originated the term Webometrics with Peter Ingwersen and who died in an accident before he could see the influence of his ideas. It is envisaged that future progress of Webometrics will prove the Web to be one of the most valuable mainstream data sources for information science.