Digital Systems for Open Access to Formal and Informal Learning is comprised of 20 chapters selected from among peer-reviewed papers presented at the CELDA (Cognition and Exploratory Learning in the Digital Age) 2012 Conference. Together, they represent the best, world class scholarship on the topic of digital systems and technologies for learning. The volume is organized in four parts: Open Access to Formal and Informal Learning, Mobile and Ubiquitous Informal and Formal Learning Environments, Virtual Worlds and Social Web Technologies for Informal and Formal Educational Settings, and Game-based Informal and Formal Learning. As digital systems and technologies for open access to formal and informal learning have attracted the attention of all major stakeholders in education, the topic has become increasingly important. These developments have led to new research challenges which are fully addressed in this volume.