Users can write (UDW) to generate arbitrary data files for EnSight parts and variables. The EnSight server provides a UDW API that can be used to write out the currently selected parts in the EnSight client part list, as well as the active variables, in a user defined format. The UDW API includes methods to get, for example, node coordinates, element connectivity, ids, variable values, and time information. A UDW can call any of the methods as it wants and create a data file(s) in any format desired. Additionally, the UDW dialog in the EnSight client has a Parameter field that provides a mechanism for passing user specified options to the UDW.