Thanks for the comments but it does seem to me strange that a complete file with family tree data, audio, photos etc cannot be transferred to the other people it involves. I did not mean that they could necessarilly add to the file itself anymore than one can to an Adobe Acrobat PDF file when the only reader is used. But the other people could see what exists, enjoy it and send further data either in hard copy, on disc or as e-mail attachments. Do UFT and other software users keep everything to themselves? Surely not. The first software company to make data transfer available will make a fortune.
In the meantime I have lots of material and nowhere to assemble it in a useful form.