The composition of interactive multimedia titles is a challenge for all advanced multimedia authoring tools. When non-interactive titles were specified by aligning the media items on a temporal axis such as time lines or tracks, now interactive multimedia titles require a non-linear temporal model. Thus, authoring becomes more complex, and the structure of a title is more difficult to visualize. TIEMPO addresses two areas: First, a temporal model satisfying the specification needs of interactive multimedia; Secondly, an interface for easy and rapid authoring of multimedia titles. This paper presents the architecture and design principles of the TIEMPO authoring and presentation environment.