I'm working on the Mac port of Unicon 2D Graphics. Basically I am trying to make Cocoa 2d graphics code for Unicon Programming Language. I spent much time on finding how to draw windows and lines without xCode. However, I cannot find how to override NSApplication-Run method. In order to implement the event handling for Unicon language, I need to override the Run method. Otherwise I need to use complicated multiple threads. I found an old version of NSApplication-run method here. The reference article could be GUI Programming without XCode in this forum. Thanks for reading this article.