Our Hospital's entire information system is running on 4D. We decided to develop and manage our own centralized computer system using 4D some 23 years ago, when 4D was still in its early days. Our database has significantly evolved and expanded since them, which in turn has had some serious impact on performance over time. Fortunately, the technological advancement of hardware and 4D has counter balanced such negative factors and given the system more room to grow accordingly. What was initially a 25 client system is now serving 120 client connections at its peak time. The 4D application manages all critical aspects of operating our hospital, including ordering, prescription and management of medical records. In addition, we use the system alongside external imaging devices, heart monitors, laboratory servers and the Osirix system, in some cases using web browsers. The user interface is kept practical and is very easy to learn. In fact we often receive very positive comments about its high quality from visiting physicians, for whom it would typically require just 5 minutes of explanation.