| According to Knuth's "TeX: The Program", the program is indeed in
the public domain.
However, it is a common misconception that you're not allowed to sell
something that is in the public domain. All that public domain means
is that you can't get copyright protection for a work. If you own a
copy of a public domain work, and someone else is willing to spend
money to buy that copy from you, there's nothing wrong in that.
Think of all the works of Shakespeare; they are in the public domain,
yet publishers continue to make money selling copies. If someone
wants just TeX, they could buy DOCUMENT from us, or they could get
free copy from somewhere else -- the choice is theirs.
Perhaps the real question is how can we expect people to buy it? The
answer is all the added value: the SDML processor, the integration of
TeX into Document, the much improved handling of TeX errors, and all
the support services that are available to Document customers.
Most especially, SDML is an order of magnitude easier to learn than
TeX.
Gary
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| > Perhaps the real question is how can we expect people to buy it? The
> answer is all the added value: the SDML processor, the integration of
> TeX into Document, the much improved handling of TeX errors, and all
> the support services that are available to Document customers.
And, at a more basic level, our TeX is not *exactly* the same as
"public-domain" TeX. All TeX programs are required to pass certain
functional tests to be called "TeX". However, we have value added
even to TeX itself -- bug fixes, message handling, a callable
interface, and probably things I don't know about -- so even our
text formatter is "a TeX" but not exactly "Stanford TeX".
Mark
|
| > And, at a more basic level, our TeX is not *exactly* the same as
> "public-domain" TeX. All TeX programs are required to pass certain
> functional tests to be called "TeX". However, we have value added
> even to TeX itself -- bug fixes, message handling, a callable
> interface, and probably things I don't know about -- so even our
> text formatter is "a TeX" but not exactly "Stanford TeX".
In fact, we have so modified the user interface to TeX that we don't pass
the test anymore! Accordingly, we don't mention TeX in any of our documentation.
(The %TEX error messages can be thought of as a 3-letter abbreviation for
"text formatter" (fortunately! (-:)).
--Brian
|