Imports: 3DS, DAE, DFX, STL, OBJ, X, LWO.
Exports: 3DS, DXF, STL, VRML, MFX.
Although it does not export Direct X because of licensing restrictions via Microsoft, it comes with the Assimp Library which converts between dozens of formats easily.
ASSIMP support is available through the ASSIMP viewer included.
Open FX is what I use for my modelling. The link is an instant download after purchase. https://www.dellsweet.com/open-fx-ofx-modeler/
Rad Sandbox: https://www.radsandbox.com