DMRI Viewer
DMRI Viewer is a utility software to view VTP file or DWI files. It supports VTP format for the geometries and NRRD/NIFTI format for DWIs (4D only)
Tract Viewer (VTP)
Unlike its name, this viewer all kinds of geometry in VTP format.
DWI Viewer (NRRD/NIFTI)
DWI viewer currently only supports 4d diffusion images. NRRD/NIFTI formats are both supported.