The idea for this book arose in Beijing in November 2009. In the months
that followed, our group assembled and started to work on the nascent book.
Sadly David Craven and Heinz Paetzold passed away in 2012. We miss them.
For his support and continuous interest in the project I wish to express
special gratitude to Terry Smith. The following people have also been instru-
mental in bringing this book from the mental shelf to the bookshelf: Thomas
Berghuis, Günter Berghaus, irwin, Gerardo Mosquera, Gao Jianping, Curtis
Carter, Desiderio Navarro, Katya Mandoki, Wang Jie, Wang Jianjiang, Brian
Winkenweder, Paula Zupanc, Erik Bachman, and Simon Tecco.