This paper describes the museuVirtual project that is developing an authoring tool for the collaborative building of nonimmersive museums in virtual reality. The rationale behind museuVirtual is based on the observation that virtual museums found on the Internet normally have very limited opportunities for user interactivity. We examine different kinds of interactivity and propose an authoring tool that allows a teacher or student to create virtual exhibits in which dynamic interactive objects and chatterbots may be programmed in a relatively easy way. This proposal is strongly based on the concepts of actor-based programming and constructivist theory, which have been applied in the last five years to teach basic programming skills to beginners. The ideas applied with success in many previous experiments using 2-D graphics are now being introduced in an authoring tool that generates VRML/Java code. The museuVirtual project is developing a tool that not only allows the students to be the organizers and curators of their own museums, but also to work collaboratively, by building such museums in a virtual distributed environment.