This paper presents a fast technique for map generation of document collections that, besides being able to group (and separate) documents by their contents, runs at very manageable computational costs, generating maps of preprocessed text in a matter of seconds. Based on multi-dimensional projection techniques and an algorithm for projection improvement, it results in a surface map that allows the user to identify a number of important relationships between documents and groups of documents that are reflected as visual attributes such as height, color, isolines as well as aural attributes (such as pitch). The map is interactive, allowing further exploration and narrowing of focus on a search task. The technique, named IDMAP (Interactive Document Map), is fully described in this paper. The results are bound to support a large number of applications that rely on retrieval and examination of document collections.