Visual Understanding Environment 3.3.0 for Mac was available to download from the developer's website when we last checked. We cannot confirm if there is a free download of this app available. This free software for Mac OS X was originally developed by Tufts University. We recommend checking the downloaded files with any free antivirus. The program lies within Design & Photo Tools, more precisely Presentation Tools.
From the developer:
isual Understanding Environment (VUE) is a concept and content mapping application, developed to support teaching, learning and research and for anyone who needs to organize, contextualize, and access digital information. Using a simple set of tools and a basic visual grammar consisting of nodes and links, faculty and students can map relationships between concepts, ideas and digital content.
You may want to check out more software for Mac, such as Visual SlideShow, Visual Paradigm Project Viewer or Visual Studio Code, which might be related to Visual Understanding Environment.
IDE
Teaching Tools