Or else the ability to save it as text (XML) in a way that will work with SVN so that we can have multiple people working on an Excel sheet saved that way and S

Or else the ability to save it as text (XML) in a way that will work with SVN so that we can have multiple people working on an Excel sheet saved that way and SVN will be able to merge it. When you try that with Excel, you get all kinds of conflicts in extra data that it's saving in the headers.