The ObjectARX® programming environment provides object-oriented C++, C#, and VB .NET application programming interfaces for developers to use, customize, and extend AutoCAD® software and AutoCAD-based products like AutoCAD® Architecture, AutoCAD® Mechanical, and AutoCAD® Land Desktop software.
ObjectARX libraries provide a versatile set of tools for application developers to take advantage of the open architecture of AutoCAD software and provide direct access to the AutoCAD database structures, graphics system, and native command definition.
ObjectARX technology helps you develop fast, efficient, compact applications. It enables power users to customize AutoCAD software and frees CAD designers from repetitive tasks. Smaller files, faster drawing operations, and smooth interoperability make an application built with ObjectARX your best choice for a design software solution.

New features you can manipulate through the ObjectARX APIs in 2009.
- A new ribbon interface displayed near the top of the AutoCAD 2009 window, provides easy access to AutoCAD tools through a collection of tabs and panels. Each tab contains multiple panels, and each panel contains multiple tools. Some panels can be expanded to access additional tools.
- The Menu Browser provides easy access to a variety of content, including commands and documents, from a single button in the upper-left corner of the AutoCAD 2009 display.
- Improved Tooltips in AutoCAD 2009 provide more information as needed. Tooltips are automatically displayed when you pass the cursor over various tools. The improved tooltips not only show the name of the tools but provide additional information, and even graphics, directly from the help system.
- The Quick Properties panel enables the user to view and modify object properties when needed them, without sacrificing screen real estate. When turned on, the Quick Properties window automatically displays an editable list of properties when you select an object. If the list of object properties exceeds the length of the Quick Properties window, passing your cursor over the Quick Properties window automatically expands the window to display all the properties.
- In addition to the previous methods for specifying the geographic location, with Geographic Location import information from a KML or KMZ file or from the Google Earth™ application.
- New Visual Tools : ViewCube™ and SteeringWheels™ tool