Clinical computing application development at Columbia-Presbyterian Medical Center has been limited by the lack of a flexible programming environment that supports multiple client user platforms. The World Wide Web offers a potential solution, with its multifunction servers, multiplatform clients, and use of standard protocols for displaying information. The authors are now using the Web, coupled with their own local clinical data server and vocabulary server, to carry out rapid prototype development of clinical information systems. They have developed one such prototype system that can be run on most popular computing platforms from anywhere on the Internet. The Web paradigm allows easy integration of clinical information with other local and Internet-based information sources. The Web also simplifies many aspects of application design; for example, it includes facilities for the use of encryption to meet the authors′ security and confidentiality requirements. The prototype currently runs on only the Web server in the Department of Medical Informatics at Columbia University, but it could be run on other Web servers that access the authors′ clinical data and vocabulary servers. It could also be adapted to access clinical information from other systems with similar server capabilities. This approach may be adaptable for use in developing institution-independent standards for data and application sharing.