Sorry about the notebook format change. Did you loose work? Conversion should be handled for you, if not it is a bug, we can fix it on 3.1. We would be happy t

Sorry about the notebook format change. Did you loose work? Conversion should be handled for you, if not it is a bug, we can fix it on 3.1. We would be happy to get more feedback on your writing process and your need, feel free to directly contact the team (IPython-dev at scipy.org, or issue on main IPython repo is fine). As for concept of "book" or collection of notebook, we are working on that (integration with sphinx)