AIDA is a freeware computer program that permits the interactive simulation of plasma insulin and blood glucose profiles for demonstration, teaching, self-learning, and research purposes. Originally developed in 1991, it has been updated and enhanced since, and made available without charge from 1996 on the World Wide Web. The freeware software can be downloaded now from: http://www.2aida.org and http://www.2aida.net as well as from numerous freeware software repositories as a non-commercial contribution to continuing diabetes education. The program, which is still being updated, has gone through a number of revisions and developments in the 16+ years since its original internet launch. During this time over 2.5 million visits have been logged at the AIDA Websites and more than 400,000 copies of the program have been downloaded, gratis (see: http://www.2aida.org/logstats). Further copies of the simulator have been made available, in the past, on diskette by the system developers and from the British Diabetic Association (BDA) — now called 'Diabetes UK' — London, England, following the BDA's own independent evaluation of the software. More than 645,000 diabetes simulations have been run via a web-based version of the AIDA diabetes simulator — called AIDA on-line — accessible directly at: http://www.2aida.net.