In the last two decades a series of international projects, using techniques as diverse as the digitisation of historical documents and the application of cutting-edge remote sensing technologies in archaeology, have transformed our understanding of a number of important cultural sites across Southeast Asia and generated a vast amount of digital data. Interoperability and data-sharing provide enormous challenges to researchers working in Southeast Asia, even as the accumulation of new knowledge and web technologies open the door for extensive multidisciplinary collaboration across various fields in the arts and the sciences. In recent years, the Electronic Cultural Atlas Initiative (ECAI) and other partners such as the University of Sydney and the French Institute of Far Eastern Studies, have sought to address some of these challenges using a range of different technologies and by undertaking training projects in several countries across Southeast Asia (particularly Cambodia and Vietnam) and also in Taiwan. Dynamic map portals have been a key component of this work. This presentation will provide an overview of that work and examine some of the issues involved, as well as outlining some of the future potential in terms of research and management provided by these digital collections and interactive web mapping applications.