Like all organisms and organizations, librarians and libraries evolve by adapting to changes and pressures in their environments. From scroll to codex to online text: every upgrade in technology is matched by an adaptation in librarianship. Nevertheless, despite centuries of evolution, the activities of librarians and the mission of libraries have remained essentially constant and are still recognizable. The pace of change in libraries has been especially rapid since the introduction of computers, and an important recent change is the advent of the “age of Google.” Heralded by the arrival in 1998 of the Google search engine, with its clean interface and superior results ranking, the age of Google is defined by the growth of Google beyond its basic search engine and the explosion of online tools that, like Google, delight users, deliver services quickly, and reflect and respond to user behavior. As the tools of the age of Google have become integral to research and other activities, librarians have adapted in three key ways: using the tools, creating and improving library tools, and grappling with the social and pedagogical implications of the tools. This special issue invites readers to consider specific instances of these modes of adaptation.