For visualization you can use Visualize and Open Cloud (this product specially designed for creating web/Saas application). These products work not only with different CAD file formats, but with BIM as well.
For developing BIM solutions you can use a wide range of file formats:
- Autodesk® Revit® files (rfa/rvt) – BimRv
- IFC files – IFC SDK
- Autodesk® Navisworks® files (nwd, nwc, nwf) – BimNv
You can get 2D and 3D .pdf with Publish SDK.