Catia V5 is a CAD system developed by Dassault Systèmes in 1998, currently widely used in the automotive, aerospace  and others industries.

Main Catia V5 file extensions are:

• .CATPart (part)
• .CATProduct (Assembly)
• .CATDrawing (drawing)
• .cgr (faceted representation)
• .3dxml (Lightened representation)

The native or neutral formats supported by Catia V5 are Catia V4, IGES, DXF, DWG, STEP, STL. Catia V5 Downgrade compatibility tool alow to convert Catia V5 models to a lower release but with some limitation : assembly not supported, multisolid not supported, some special entities not supported, parametric information lost.