\chapter*{Acknowledgements}

The book is based on Florian Dold's PhD thesis. We have removed the parts that
are not crucial for GNU Taler. Also, unlike the thesis, the GNU Taler project
continues to be updated, so this books is expected to be kept up-to-date with
the latest developments.  Nevertheless, Florian Dold's contribution to the
text remains fundamental.

We would like to thank Moritz Bartl for helping with the funding for Florian's
thesis and GNU Taler in general.  Bruno Haible provided generous support for
the GNU Taler team to visit meetings of the W3C's Web Payment Working Group.
We also thank Ashoka, the Tor project and the Donaukurier for their support.

This work benefits from the financial support of the Brittany Region (ARED
9174) and the Renewable Freedom Foundation (RFF).  

We thank the Bern University of Applied Sciences for continuing to host the
GNU Taler servers.

We thank to Cristina Onete and Jeff Burdges for their collaboration on the
provable security of GNU Taler.

We are grateful to the GNU project, in particular Richard Stallman, for their
support of this project.  We also thank all GNUnet developers and GNU Guix
developers, especially Hartmut Goebel, Nils Gillmann, Gabor Toth, Ludovic
Courtès and Andreas Enge.