1. Global cloud resolving model (gcrm),
https://svn.pnl.gov/gcrm
2. Paraview,
http://www.paraview.org/
3. Visit,
https://wci.llnl.gov/codes/visit/
4. Visualization toolkit (vtk),
http://expression-tree.sourceforge.net/
5. Math expression string parser (mesp) (2004),
http://expression-tree.sourceforge.net/