During the last decade computer-controlled systems have shed a new light on our industry's environmental control systems. Though quite experimental in their first applications, much has been learned in the years since their inception. However, the surface has just only been scratched and present applications as well as proposed new ones will in the years to come provide us with an invaluable and irreplaceable tool. At present, an environmental computer installation has many functions. Nine of the most interesting and their applications are reviewed here.