is an open source (free) port of IBM's Visualization Data Explorer software.
This is a set of tools for visualisation, which include isosurface and
isocontour generation, volume rendering, and cutting planes.
Binaries are available for
Linux, Solaris, IRIX, AIX, and Windows 95/NT (using Cygwin). As well, the source is
available for porting to other platforms. Uses X11 (X Windows).