Following on from the enormous success of Milestones in Cell Division in 2001, we are delighted to bring you Milestones in Development, a supplement that highlights the key discoveries in developmental biology over the past 100 years. Milestones in Development is a collaboration between Nature, Nature Cell Biology, Nature Reviews Neuroscience, Nature Reviews Genetics and Nature Reviews Molecular Cell Biology.

The topics for the Milestones were chosen with the help of 34 developmental biology experts, and the articles were written by editors across the Nature Publishing Group. In particular, we highlight studies that provided insights into specific developmental mechanisms, many of which are conserved across the animal kingdom. The Milestones are available online at www.nature.com/milestones/development.

The print supplement also contains articles from the participating journals, and there is a more extensive library on the Milestones in Development web site. A digital edition of the entire supplement can be downloaded free of charge from the Milestones in Development homepage (numbers are limited, so reserve your copy now!).

To guide you in your further reading, the Milestones are linked to extracts from Developmental Biology by Scott F. Gilbert, and we are indebted to Scott Gilbert and Sinauer Associates for providing exclusive free access to this material. We also wish to acknowledge the support of our sponsors: the March of Dimes, the National Institute of Child Health and Human Development and the Juvenile Diabetes Research Foundation. As always, Nature Publishing Group carries sole responsibility for all editorial content.

We hope that you enjoy our journey through 100 years of developmental biology!

Katrin Bussell, Senior Editor, Nature Reviews Molecular Cell Biology
Natalie DeWitt, Senior Editor, Nature
Alison Schuldt, Senior Editor, Nature Cell Biology
Magdalena Skipper, Editor, Nature Reviews Genetics
Heather Wood, Senior Editor, Nature Reviews Neuroscience