Good morning/afternoon, I am having a problem with XQuartz 2.7.2 (but also latest) and a program I am deploying, specifically due to libpng15.15. I envision a more general issue, as my software also depends on other X libraries. I am compiling on 10.8/XCode 5, freshly installed. 10.8 comes with X11 libs but no headers, so I installed XQuartz and compiled without a problem. The application runs on this machine. I then packaged my .app and tried to run it on a customer's machine (10.9, upgraded from 10.6.8) but I get a Compatibility error in libpng15.15 (claims 25.0.0, but wants the one of the XQuartz I had, 27.0.0). I did change the path to the proper one with install_name_tool. I think I see where the problem is, namely, I am binding to the XQuartz libpng (27.0.0), but this is not available on the customers' 10.9, where the libpng is only 25.0.0. However, I fail to see what's the proper way of dealing with it. Should I - unpack only the .h files out of XQuartz (or get them in any other way) and link against the .dylib provided by Apple on 10.8, or - use XQuartz to compile and link, then ship XQuartz .dylibs as private libraries in my .app, or - other options ? I am sure I am not the only one having faced this problem, so I assume a best or common practice exists. Note that I can't deploy XQuartz on the customer's machine, and I should not need an X server. The app is in Qt, running native, but some libraries I am using do need X libraries, in addition to libpng, freetype etc... Thank you for your attention and help, Stefano Borini