Wikipedia
VisTrails
VisTrails is a scientific workflow management system developed at the Scientific Computing and Imaging Institute at the University of Utah that provides support for data exploration and visualization. It is written in Python and employs Qt via PyQt bindings. The system is open source, released under the GPL v2 license. The pre-compiled versions for Windows, Mac OS X, and Linux come with an installer and several packages, including VTK, matplotlib, and ImageMagick. VisTrails also supports user-defined packages.