Jacko thank you for giving Tonfotos a try!
Sure I know what sidecar means 🙂 And I think this approach is quite outdated. It started long ago when it was not common to write metadata inside JPEG, and not much applications were compatible with JPEG’s with XMP metadata inside. Today this is part of JPEG standard and there is no point writing metadata separately if you can write it inside file itself, which is not a problem at all. Even photo cameras are writing XMP information inside JPEG these days, even though they have not much useful information to write there.
Probably I did not express myself right. It is not that Tonfotos does not want to change original images at all, it is just that this editing functionality is not first priority. The priority is viewing, organising, cataloguing, etc., and all that just does not require writing into files, mostly reading.
So, based on your answer, I understand that you mostly talking about tags. And that is true, Tonfotos does not fully support tags at this moment (and that is the reason this thread was started by Bobb ). It can read from XMP and show tags, but it cannot edit it, and obviously, it does not write edited tags into images and/or sidecar files.
This feature will eventually be implemented, it is just little bit further down the roadmap. And when it will be, obviously, tags will be stored inside images metadata, otherwise there is no point in having this functionality at all. We already have albums, and the only difference between albums and tags is that tags are stored in images, while albums - in database only.
So, apart from tags, is there any other metadata you would expect to see embedded into images?