This document provides an overview and agenda for an AR development event taking place in Amsterdam on April 17, 2010. The event brings together experts from different areas of augmented reality to share ideas and work towards more open and interoperable AR platforms. The day will include short introductory talks on topics like using public data for AR applications, 3D modeling, and cultural heritage. It will also feature parallel workshops for participants to discuss specific technical challenges in smaller groups. The goal is to connect expertise from diverse backgrounds and help propel AR beyond isolated labs towards widespread adoption.