3D Iges Viewer – ABViewer 7.3
Professional 3D Iges Viewer to import and read *.igs format files. 3D Iges Viewer can print and convert IGES to BMP and other formats.
Free to use additional library is required for IGES and STEP/STP formats (7.5 MB):
http://www.cadsofttools.com/download/converter3df.zip
IGES - The Initial Graphics Exchange Specification defines a neutral data format that allows the digital exchange of information among Computer-aided design (CAD) systems.