This workshop will bring together and help establish an emerging community with the common goal of four dimensional reconstruction of mammalian development. A number of longstanding questions surrounding the early development of mammals have been inaccessible to molecular research due to technical limitations and poor physical accessibility of these processes. How is the body plan established in the early embryo? How is morphogenesis coordinated with lineage specification? The recent revolutions in advanced light microscopy and bioimage informatics have opened up completely new avenues to address these questions and make fundamental advances in our understanding of the developing mammalian embryo.