OpenZinc contains several differences from Zinc Application Frameworks 4.2 on which it is based. Most of these are simply to accommodate newer compilers and C++ standards.
The only changes in the public interface of the library are; 1)the change of UI_WINDOW_OBJECT member UI_REGION true to UI_WINDOW_OBJECT member UI_REGION trueRegion to avoid a conflict with bool true and 2) the change of DEVICE_IMAGE DM_POSITION to DEVICE_IMAGE DM_POSITION_IMAGE. Other than that code written for Zinc 4.x should compile fine under OpenZinc.
Additionally, *.cpp and *.hpp files generated by OpenZinc Designer are slightly different than those generated under Zinc Designer 4.x. To modify older versions of these generated files they simply need to be opened and saved with the OpenZinc Designer. This will allow the generated code to be compiled under newer compilers (as well as older ones).
Other important changes include provision of code within header files to allow compilation under linux and a number of additional makefiles for new compilers.