MicroDicom - DICOM viewer. MicroDicom is a free DICOM viewer. Export to the most common picture formats, movie, clipboard. It is equipped with most common tools for manipulation of DICOM images.
STP Viewer - Free STP Viewer - free software that lets you view 3D STEP files (.stp, .step file format).
Horos - A free, open source 64-bit DICOM medical image viewer
eDrawings Viewer - View, print, and review all types of eDrawings files Built-in Viewer
Weasis - Weasis is a multipurpose standalone and web-based DICOM viewer.
Vesalius3D - Vesalius3D is a toolkit for visualization of patient specific anatomy