Microsoft Windows has supported a feature called Shadow Copy since Windows Server 2003, using Windows 2000 or newer as the client.
Shadow copies, better known as “Previous versions”, by many users are kind of snapshots of a filesystem (“drive”, for Windows users) taken every so often. It is not a replacement for backups or RAID, just a convenient method to access old versions of your files. Thin of it as a revision control system for any file, save for “revisions” are taken at time intervals instead of evey time there are changes, which means not all the changesets are “captured”.
On the Unix world, you can get more or less the same features, albeit only locally (not for NFS or Samba shared folders), by using filesystems such as ZFS, HAMMER (apparently, only available on DragonFly BSD), Btrfs, Zumastor and many others. The main problem being adoption of those solutions is marginal, and not available through the network (“shared folders”).
Sun (now Oracle) implemented a “Previous versions”-like feature for ZFS snapshots in Nautilus in October 2008:
KDE once had something like that but for the ext3cow file system. It was an application called Time Traveler File Manager (user manual, interface design and details) by Sandeep Ranade. Website is down and ext3cow is effectively dead now.
By this time you probably have guessed my wish for today: implement “Previous versions” support for Samba, ZFS, etc in Dolphin, the KDE file manager, or even better: in KIO, so that it is available to all KDE applications.