The Calibre viewer family, represented by DESIGNrev supports a wide variety of file format, thanks to a very flexible read/write interface. DESIGNrev shares the Calibre batch reader. So it supports reading and writing GDSII and OASIS files. With the fdi expansion, DESIGNrev also reads foriegn layout format such as OpenAccess, Milkyway and LEF/DEF formats.
If you want additional formats, you can develop a translator using the powerful Tcl interface. We have a sample DXF script reader up for your request. Please contact Mentor Graphics support person to get the file.
If you have the higher tier viewer products such as MDPview, LITHOview or WORKbench, you can also open fracture formats and jobdecks with the viewer.