First steps toward what you want exist in the next OS X: http://www.apple.com/macosx/lion/#versions http://www.apple.com/macosx/lion/#versions I don't know if

First steps toward what you want exist in the next OS X: http://www.apple.com/macosx/lion/#versions http://www.apple.com/macosx/lion/#versions I don't know if it has diff capabilities though.