There is no need to dig into details. I know Palm OS was single tasking, but save state or suspend, the effect was the same: you never closed an application, you just started a new one. When you then went back to the previous one, it resumed from the same state, i.e. it never started from zero.

With a handful of very rare exceptions, applications on neither OS even had the "Exit" option. On Symbian, it was even actively discouraged (by programming guidelines) for applications to have that option.

I have (thank Zarquon!) never owned a Symbian phone and have no extensive user experience with it, but I have a lot of programming experience and that alone made me never want to touch Symbian with a barge pole if I could avoid it. We had to go through hoops to follow the guidelines, such as #if-#endif to make "Exit" available for debugging but taken out from the release build. Yuck!

This is what now annoys me about Android. There is the "Back" button that, if you press it enough times, eventually closes the application. But does it really? The fact that you can never be sure is what I find rather irritating.