The major European fusion facilities, JET, Tore Supra and Asdex Upgrade, have a 30-year history from conception to the present day. This period has seen a rapid evolution in computer techniques. Experience has shown that IT architectures and standards adopted early in the construction phase of a project are carried into the main programme and affect the project for its entire lifetime. In this paper we select a few of the more portant computer-related lessons we have learned in Europe, particularly with respect to the EFDA-JET facility, and we make recommendations towards the next generation of machines.