Release Date: April 20, 1999
NPDS is as much a concept as anything else. When the Newton was conceived and then sold a fundamental tenet of its design was its portability. Yet, never during the course of its short and brilliant lifetime was it actually PORTABLE.
You could connect to any desktop.. as long as NCU or NBU or Xport was installed.
You could print out information.. if you had a compatible printer.
You could let others see your schedule.. if they had a fax to send it to.. or a Newton of their own.
Etcetera, Ad Nauseum, Ad infinitum...
NPDS was designed to address some of these shortcomings and also as a proof of concept that PDAs should have HTTP servers embedded in them as a means of communicating with the outside world.
So, to answer the original question: "What is Newton Personal Data Sharing?"
NewtonOS Personal Data Sharing is a suite of software for the Newton that allows you to transparently share Notes, Calendar Entries, and Cardfile entries with clients on the WWW. It's a battery powered webserver that sports features often reserved for "big iron" servers.. scriptability, security, dymamic content generation, instant messenging, etc..