alt Hacker NewsIt was really the touch screen UI, which was brought to market by Apple. Always been curious if it was developed there or if like the desktop windowed UI it was pioneered elsewhere.
Prior efforts were menu oriented or attempts at desktop UI on a tiny screen, like WinCE.
The basics of PalmOS were fairly touch oriented but resistive rather than capacitive, which made a difference usability wise. Menus though could get desktop-y.
I think the big diff was assumption of handwriting as the UI. Latter palm treo had a keyboard like blackberry, I used several generations of those before trying the HTC g1 :).