* the editor keeps a max of N tabs open using least-recently-used
* browser-like navigation by clicking into symbols combined with forward/back history
The autosave part was weird at first, but it makes so much sense. Why bother with explicit saving, prompting "do you want to save", manually closing tabs, etc. Combined with the navigation features, you never care which tabs are open. Edit history plus version control are much better than a simple save/discard model.