You can easily convert Kaydara 3D files (.fbx) to a common 3D Object file format (.obj) with the FBX Converter, a utility you can download for free from Autodesk website. Nevertheless, both formats are well supported , so it should not be a problem to find other programs capable of fbx to obj conversion.
Open FBX file Open OBJ fileA web-based freemium 3D computer graphics software
A Mac version of the popular modeling tool
An FBX convertor utility from Autodesk
A free online 3D model conversion service
A 3D CAD translation software