A collaborative computing environment supports groups of people as they cooperate to achieve their goals. This paper presents a system architecture to support the application areas in collaborative authoring and editing. An experimental platform, called the i-Code system, has been developed. It is a Java collaborative integrated development environment (IDE) tool designed to help collaboratively build Java applications for collaborative computing. Not only the IDE itself, but also the Java applications, are collaborative. Furthermore, in a computer-supported cooperative work (CSCW) environment, event broadcasting is a common operation in an object-oriented software system. In a multi-user case in particular, due to scalability, such operations are expected to be more quickly and reliably executed. In this paper, we also provide a study of issues related to event broadcasting in a Java collaborative computing environment over the Internet. We address how these issues happen and propose solutions for them.