OpenDX is described as 'gives you new control over your data...and new insights into their meaning. Yet OpenDX is easy to use because it lets you visualize data in ways you've never dreamed of--without getting bogged down in the technology'. There are four alternatives to OpenDX for Linux, Windows and Mac. The best alternative is Paraview, which is both free and Open Source. Other great apps like OpenDX are GiD (Paid), VisIt (Free, Open Source) and Mayavi (Free, Open Source).