MayaVi is a free, cross platform, easy to use scientific data visualizer. It provides a GUI to ease the visualization process, is written in Python and uses the Visualization Toolkit (VTK) for the graphics.
Open source project that offer summary and download services on this page is a project that carry out their development work on other open source development sites. Their work is linked to this page via a feature called OFI, and their work is not carried out here on OSDN site.