Apple gets back to basics in Mac OS X Lion | Operating Systems | MacUser | Macworld: Another new Lion feature Apple announced, “Resume,” is also an ode to iOS, but it will likely have an even larger impact on the Mac. Just like switching between apps on an iPad or iPhone, or even restarting the device, Resume is Lion’s official support for third-party Mac apps to pick up right where they left off, even after a restart. That’s not merely a good idea in iOS, it’s just a good idea for any reasonably complex computing device—especially one that is designed to multitask and juggle many apps and open windows with ease.
Speaking of recovering your data, a pair of new features will make it easier to continue working with individual documents and recuperating lost data—key requirements of any worker bee who needs more power and flexibility than iOS typically offers. Auto Save will allow apps to automatically save your work as you create it, while Versions brings the continuous backup concepts and interface behind Time Machine down to a per-document basis. You will be able to step back through the history of the current file on-the-fly and easily revert to a previous iteration.