Cross platform file server with flslint-style duplicate link

[1clue]

Hi,

I don't know where else to put this so it's going into unsupported software.

I actually have 4 platforms going in my home: Windows 8, Mac OS 10.8, Android 4 and Linux.

I'm looking at backup and file sharing solutions that can save space. I don't see what I want out there, and I'm considering a Linux solution.

Here's what I want:

I'd like for duplicates to be eliminated automatically, but changes to a duplicated file to be tracked. The first part brings to mind FSLint, but once two files are linked together and then one of them edited, I want the other(s) to be the original version.

As well, I would like for the changes to be applicable to all four platforms. Meaning, my wife can put a file from Windows 8 and get it back on her phone and it still makes sense.

I'm thinking along the lines of subversion or git, but I think those would be unmanageable as a system backup or even as a file server.

Is there something out there that can handle this? At this point I'd even go with a commercially available solution.