Richard Fox Chairman, Scientific Programme Committee Between 25th and 29th September, 1988, 243 people who either apply or research the use of computers in fermentation gathered together at Robinson College, Cambridge, UK. They came from 30 countries. The conference brought together two traditions. Firstly, it continued the series on Computer Applications in Fermentation Technology (ICCAFT) inaugurated by Henri Blanchere in Dijon in 1973 and carried forward in Philadelphia and Manchester. Secondly, it brought the expertise of the many members of the International Federation of Automatic Control (IFAC), who focused their attention on biotechnology at Noordwijkerhout in the Netherlands in December, 1985. I am happy to say that the tradition carries on and a successor meeting will hopefully take place in the USA in 1991. If you find these proceedings useful or stimulating, then we hope to see you there. We set out to make ICCAFT4 a close-knit friendly conference. We housed all who cared to in Robinson College itself and organised no parallel sessions. Because we, the organisers, experience difficulty with the jargon of our colleagues from other disciplines, we asked Bruce Beck to present a breakfast tutorial on modern control and modelling techniques, and we set up informal panel discussions after dinner on two evenings. Neville Fish chaired a forum on the microbiological principles behind models, while Professors Derek Linkens and Ron Leigh led a discussion on expert systems in control.