All three visualization packages are used in a very similar way. Users create a flow chart within a sophisticated graphical user interface, consisting of modules connected by paths that direct the flow of data. It makes many copies of data and requires a large amount of RAM and hard disk space to run. It is common to have hundreds of megabytes of RAM on any machine running these programs. The advantage of using this data flow model is that modules can be quickly rearranged, added, written, and adapted without knowing the entire system.
Economic factors are the primary reason for the shortage of visualization software on the market.
But when the same software is available on a Windows or Linux PC, the pricing structure is turned on its head. Now that this shift to lower priced, high performance computers is in progress, the best we can do is use the available tools and wait for the market to adjust to the new realities. Over the past decade, the large amount of data available in 3D, time dependent data sets was the primary problem in scientific visualization. As datasets increase in size it becomes an increasing challenge to manage, display and interpret. Perhaps the most dramatic, immersive VR technology is the CAVE developed in the Electronic Visualization Lab at the University of Illinois, Chicago and Champaign-Urbana.