This article reports on patterns of links from and to the Web sites of 100 U.S. academic and public libraries with regard to the originating and targeted URL domain categories. Libraries, grouped into small and large by their collection size, were found to have numbers of inlinks proportional to their size, but public libraries, and particularly the smaller ones, hosted relatively fewer outlinks. While public libraries link largely to and attract links mainly from the .com and .org domains and U.S. regional sites, academic libraries link to a variety of domains, including .edu, .com, .org, and some overseas sites. Academic libraries also draw inlinks mainly from .edu and .com sites. The results reveal that there is little interaction between public libraries in the United States and U.S. universities, and this calls attention to the need for more collaboration between the two types of organizations.