Some of hte ideas from http://www.w3.org/1999/04/Editing/ http://www.w3.org/1999/04/Editing/ might come in handy there. What realistic usage scenarios are there

Some of hte ideas from http://www.w3.org/1999/04/Editing/ http://www.w3.org/1999/04/Editing/ might come in handy there. What realistic usage scenarios are there for multiple clients concurrently uploading (parts of) the same file?