This book discusses the use of e-learning in the progresses towards Sustainable Development (SD) or Education for Sustainable Development (ESD). Almost three decades after the concept of sustainable development appeared, 2014 is the year where historical goals should be reached, since it is the last year of the United Nations Decade on ESD. Within this decade, research, projects and educational initiatives were developed and deliverables were achieved. Using e-learning is becoming widely accepted in formal and non-formal education proving to have the potential to be effective in expanding Education for Sustainability (EfS). Lifelong learning, adults' education and the huge increase in the use of the Information and Communication Technologies (ICT) lead to e-learning's significant role within the learning and education processes.