ObjectARX applications can use MFC dialogs, WinForms, and WPF, manipulate AutoCAD menus, and control system variables.
Each application may require its own AutoCAD variable settings during the course of its execution. The user can also change variable settings and expect them to retain the established value. An application cannot assume that an AutoCAD variable will be in a certain state prior to the application's entry point or after giving control away to the user or other applications.