Visio - The Interaction Designer's Nail Gun
http://www.guuui.com/issues/02_03_02.php

Olsen, Henrik
GUUUI
2002

Abstract:

The reason why Visio is the favourite prototyping tool of many interaction designers is because of its ready-made interface objects, you can drag-and-drop onto pages and its ability to link pages together and export them as web pages. But what distinguishes Visio from other prototyping tools is its use of layered backgrounds.