Software visualization is nifty stuff; but is it the powerful cognitive tool it is often assumed to be? This chapter attempts to moderate the understandable enthusiasm for software visualization and to raise some of the questions for which the discipline doesn't yet have answers. The chapter is structured as a list of questions with discussion. The questions are not a comprehensive analysis of cognitive challenges in software visualization. Rather, the chapter attempts to provide a list sufficiently provocative to give designers pause, in order: (a) to establish that good software visualization isn't simply a matter of mimicking paper-based tasks or doing what is technically easy---and certainly isn't `solved' yet; but also (b) even simple tools can improve software comprehension, if they're the right ones.

This paper describes an extensible multimedia electronic mail system called Montage which is based on the X Window System. Montage supports the composition, transmission, and viewing of structured documents consisting of virtually any type of medium. Further, users can at runtime extend the system easily to support new document types, including text, images, audio, video, executable programs, and commercial file formats. KEYWORDS: Multimedia, electronic mail, X Window System. INTRODUCTION: WHY MULTIMEDIA MAIL? In the past decade, the proliferation of fast, inexpensive, networked computer workstations has produced an explosion in the use of electronic mail. Electronic mail systems have traditionally been limited to the transmission of simple textual information. More recently however, as computer workstations have increased dramatically in power and as the use of windowing interfaces becomes more widespread and standardized, the capabilities have emerged for the composition, transmis...

In this paper we present a new approach for monitoring and visualization of parallel processing systems. Instead of measuring the system and presenting to the user a variety of performancefigures and visualization displays afterwards, in this user-oriented approach the events and features of interest may be selectedbefore instrumentation and measurements. Different techniques for this a priori filtering of events areprovided, ranging from a direct manipulative selection in agraphical, hierarchical representation of the program and the architecture, to a textual, rule basedselection. Real-Life Metaphors in visualization make this approach particularly suited for so called novice (i.e. non-expert) users, thus suggesting teaching as one of the major fields of application.