FDU files are associated with NaturalONE, a software development framework for Microsoft Windows. FDU files store data used by NaturalONE for internal processing.

FDU is a binary format. Data in FDU files cannot be viewed directly or manually edited by users. This is a internal data format native to NaturalONE. FDU files cannot be converted to other formats. FDU is a format proprietary to Software AG.