OpenDCL is an open source application platform for AutoLISP programmers who want to replace AutoCAD's limited DCL (Dialog Control Language) user interface language with a rich set of modern Windows user interface elements. AutoCAD application developers and customizers can use OpenDCL Studio to interactively design modern and professional user interface elements for use by their AutoLISP code in AutoCAD. The OpenDCL Runtime component is deployed with the application, and provides the necessary runtime framework inside AutoCAD for end users of the OpenDCL application.