The Agenda 21 is the United Nations' action plan for the 21st century in favour of sustainable development. Launched at the Rio Earth Summit in 1992, its 40 chapters include social, economic and ecological actions to be implemented by local authorities, governments, but also by corporate companies and services. Twenty years after the Earth Summit, our proposal is to apply the Agenda 21 to library management and development and to move on to the global or sustainable library. Based on the concepts of global performance and corporate social responsibility, we describe five main dimensions, e.g. social, societal, ecological, commercial and economic performance, and encourage a conceptual framework for the evaluation, management and development of libraries and information services. Special attention will be paid to modern information and communication technologies (ICT). With regards to Agenda 21, the role and impact of ICT is complex. The focus on technology bears the risk of neglecting other aspects but ICT may be extremely helpful for the development of the global library. It should be evaluated against criteria from Agenda 21, as a tool but not goal on the way to sustainable development. This includes aspects like the ICT's social impact and recycling. The paper will provide a new approach, a conceptual framework that may be helpful for the development, evaluation and education of library services.