Widespread use of the Internet for education and research is yielding many opportunities for network-based synchronous collaboration. For example, the Java runtime environment provides a platform independent vehicle for new collaborative applications. While many toolkits are becoming available that support development of collaborative applications, they do not enable collaborative use of existing single-user Java applets, a process called collaboration transparency. This paper discusses two approaches to collaboration transparency: display broadcasting and event broadcasting. We then consider the suitability of each within the context of the Java runtime environment. Unfortunately, simple modifications to the standard Java class libraries as they are currently implemented are not sufficient to support collaboration transparency. We describe the problems and suggest solutions.