Three years ago (has it really been that long?), I published a quite detailed (and at times, mildly emotional) retrospective article on the history of Palm and the Palm OS, which I still think is a pretty decent read. For a different perspective on the matter, there’s now an excellent article series at LowEndMac.
Palm Computing was largely the creation and vision of one man, Jeff Hawkins. Palm first brought tablet computing to consumers in the form of PDAs (but was beaten by Apple and its scions). The later – and more momentous – goal was to bring consumers to PDAs through simple and very fast user interfaces. This second goal brought us the original Pilot and an entirely new form-factor that millions embraced.
It was only until the introduction of multimedia-rich smartphones that Palm stumbled, though it was one of the leading manufacturers.
An excellent different and detailed perspective on the history of Palm.