besides milkshape not really. You can use blender to convert some models, and you should be able to open .fbx and .obj in MED. You can make .fbx and .obj with A LOT of software.
I use silo for modeling a lot. I use modo, maya, zbrush...the list goes on...
I thinbk you can import from 3dstudio max also
You can import .obj from the open source modeling program called WINGS