I discovered last night that Mono does not contain certain parts required to make ExIf35 work on other platform, mainly, the basic parts of the Windows Presentation Foundation, which allow the metadata writing components that I use to function. At the moment I have no idea how I am going to proceed. It has crossed my mind to neuter out Form3 (the thing that writes exif to the files) and ship the application as is for other platforms, but that is somehow less than optimal. I have also considered doing everything normal, but then creating a special form3 that will write a .xmp sidecar file for each image, for later reintegration by another application. At the moment I am attempting to locate any way possible to write those values to the file that doesn’t use any part of WPF, so that there will be a chance that Mono can use it. My fear is that I will end up having to learn how to write directly to the image file in byte form to implement all of these fields. It would be neat to learn how to do that, but at the same time, quite a huge annoyance. So for now, sorry Mac users, it isn’t going to happen any time soon 🙁