Okay So my problem is that I have found this code (C++) that uses both OpenCV and WxWindows. It's not my program but an OpenSource program that i'm trying to write a small plugin for. But I have no idea how to get Xcode to recognise the headers for these two programs. I'm pretty sure that I have installed them both correctly, but I still get these issues: 'wx/wx.h' file not found 'cv.h' file not found 'wx/wxprec.h' file not found. I have not been able to find any help on that is related to Xcode 4, so I'm hoping you can help me.