ObjectDBX ™ is the subset of the ObjectARX® libraries that is required to define custom database objects and entities. An Object Enabler defines custom DWG and DXF database objects and entites using only the ObjectDBX portion of the ObjectARX SDK. Object Enablers have a .dbx extension and can load in any RealDWG® host application, such as AutoCAD®, DWG TrueView™ , Autodesk Inventor®, or a third-party host application built with the RealDWG SDK. Object Enablers are built to be distributed to anyone using a DWG file containing instances of custom objects. ObjectARX developers are encouraged to use Object Enablers for custom objects.
The RealDWG SDK, formerly known as the ObjectDBX SDK, is licensed separately from ObjectARX and allows developers to write host applications that can read and write DWG and DXF files without AutoCAD. See the autodesk.com Developer Center for more information about the RealDWG SDK.