David said:
It has to be. You can't even develop software let alone sell it if it
will not run on any existing system.
Not so. For example, long time ago there was a software weather prediction
package developed that, with the current computing power, could 'predict'
the weather about 1/10'th as fast as the weather actually transpired.
Now, you might not think that's very useful but it was useful in verifying
various weather prediction theories and the fact that your 'confirmation'
had already taken place was not particularly a problem, for that purpose.
However, it's intuitively obvious that more powerful computers would make
the package useful in another arena, actually PREdicting the weather and
the need for more powerful computers, based on seeing this software
package, was not lost on the designers.
The more generic case is Bob and Bill discussing a new software package
with Bill noting nothing available today is powerful enough to run it and
Bob retorting, "don't worry Bill, there will be by the time YOU get
finished with it."