Several versions have been designed, some simple with just two buttons, some with larger LCD screens and more buttons. The protocols could also be run in extensions to existing PDAs. The wallets have an infrared interface to make use easy. They use smartcards as money storage. CAFE started in December 1992 and ended in November 1995, with 3 months' official extension for the trial, which is still taking place on the premises of the European Commission since October 1995.
Final reports are still to appear.
It is hoped that a few of those will take over the system after the end of the trial. More detailed technical information should soon be available. For preliminary versions, please mail .