When the abacus webpages were originally created back in 1995, I had helpful suggestions from many people.
A great debt of gratitude goes to Ryerson Professor Emeritus Augustine Lee, who once upon a time showed me my first real, live abacus, without which xabacus (program that ran on X11, the X Window System) would not have been possible; for supplying invaluable documentation on using it, portions of which were shamelessly plagiarized; for the Chinese ideograms; and for testing xabacus and providing helpful comments on improving it and for donating the Lee Abacus and manual to me.
Thanks also to Nick Colonello, former sysadmin at the Electrical Engineering Department at Ryerson and technical-support person, for beta testing xabacus; and to the very cute Eva Dudova, who has expertise in unmercifully crashing applications (has a future as a beta-tester).
To Arthur van Hoff, Sun Microsystems (now at Marimba) all-round Java Jenius, for suggesting the "value" applet-resource and porting the Java Abacus to the beta API; and Jonathan Payne, Starwave Corp. (now also at Marimba, for suggesting the digital display of the abacus value (incidently, Berry Kercheval, Xerox PARC, had suggested it for xabacus).
To the vigilance of Robert Garry and Sandy Sledge who noted that the figure representing the number 87,654,321 was incorrect; and Alex Wu for the elaborate description of proper fingering technique in using the Chinese and Japanese abacus. To Virginie Clayssen and several others (I will one day have the time to add your names here) for corrections to my pages. An apology to those who have actually tried to learn addition on the abacus despite my typographical errors in the tutorial pages but especially to John Wolfe who mailed me the corrections.
To Anonymous, whose abacus photographs (from the E-bay auction), I incorporated into the introduction and to the countless who have emailed words of praise that just make my day.
And finally, thanks to James Gosling, for Java, and thanks to those who have written X-applications and demo Java applets, from whose code I have learned the art of X and Java.