(As a heads up, I've hardly used any versions of OS X newer than Snow Leopard. So, I might be missing something obvious here).
I recently installed Mountain Lion and after that Mavericks. While on Mountain Lion, I noticed the "new" versions and autosave feature (released in Lion, right?) that you could access via the context menu of a file in Finder or the arrow next to the file's app's window title.
But, now that I'm in Mavericks, I can't find it in either of these places.