To add graphical features not currently supported by ACUCOBOL-GT, you can use one of the system development kits offered by operating system vendors. For example, the Windows Software Development Kit (SDK) from Microsoft supports extensions to applications running under Windows. Using the SDK, you can build C routines that provide extra features, and then call the C routines from your COBOL application. ACUCOBOL-GT is fully compatible with the Microsoft Windows SDK, so the two are readily integrated.