We have received much valuable assistance from many people around the world; it is impractical to name them all but we wish to record our gratitude to them. We particularly thank all the people who assisted with the MUA investigations; the key server and ftp site administrators; the software authors who let us place their work on the CD-ROM and TERENA, UKERNA and SURFnet who funded it. Some individuals made especially substantial contributions. In alphabetical order, they are: Dennis Jackson, Teun Nijssen, Alan Robiette, Sue Weston and Jonathan Wignall. Finally, we thank Oxford and Cambridge Universities for letting us use their time, equipment and network bandwidth to support our portions of pgp.net.