JACIE -- an authoring language for rapid prototyping net-centric, multimedia and collaborative applications. The World Wide Web (WWW) is now accepted as a de facto standard for human-computer interaction and human-human communication, so it is desirable to develop net-centric, multimedia and collaborative applications. In this paper, we present a new scripting language, JACIE, designed to support rapid prototyping and implementation of such applications. The support for the management of multimedia interaction and communication in collaborative applications is highlighted. JACIE facilitates such support through the concepts of channels and a collection of interaction protocols. A template-based programming style is adopted by JACIE, using a single program for both client and server, and platform-independence achieved by employing Java as the target language. All these features characterise a desirable multimedia software engineering tool.