VMAP is based on the HDF5 file format, which is also an open definition and can handle large, complex and heterogeneous data. HDF5 uses a "file directory" like structure that allows you to organize data within the file in many different structured ways, as you might do with files on your computer. The HDF5 format also allows for embedding of metadata making it self-describing. shows the schematic of the HDF5 file structure.
Since HDF5 is an open source file format, developers have access to the HDF5 C++ libraries and the HDF Viewer to view the VMAP files. However, if a simulation software inherently supports the HDF5 file format then VMAP can be viewed directly with the simulation software viewing tool. The figure on the right shows a schematic of the data storage structure followed by VMAP.