Cassius wrote:

Even if a PIM has been around a long time, development may suddenly end. Jot Plus is an
example that I have used for years, but its developer has said he has found more
lucrative pursuits. Yet it is still being sold on its Web site, kingstairs.com
.

Serious problems include:

A new OS version may not support a program that has
ceased development. Examples: GrandView, GoBack.

The solution in this case is to,
if possible, keep the old computer and OS, just in case you need the material you stored
in the moribund PIM, or only use PIMs that can export to a standard program such as Word,
and do the export in the old OS where the moribund PIM still works. (Luckily, GV files
can be converted and imported into Inspiration with rather good results.)

In
government and industry, new OS and software versions can result in extreme expenses
and errors when a model developed in an earlier version of an OS or program (e.g.,
Excel) has to be rewritten for the new versions. My approach, in cases when the model
was unlikely to be used much, or at all, was to keep the old computer with the old OS and
software rather than to rebuild the model. Of course, this only works if the original
model builders DOCUMENT the OS and software they used. Regrettably, this
often/usually doesn't happen.

Huh. So that's why so many government departments still runs Windows 2000