Re: Document reasonable portability targets

[Paul Eggert]

Thanks for redrafting that.  It looks much better now.  Some further comments:

> +currently ported to are probably HP-UX 10.20 and IRIX 5.3, though we
> +are not testing these platform very often.

platform -> platforms

> +will not support all versions that are at most three years old, but only

I had trouble parsing the sentence that contains this line.  Perhaps replace
the entire line with the word "supports"?

> +people from their developers or users community contributes support to

Change to "developers or users contribute support to".

> +As of 2011, the list of supported platforms is the following:

The actual list talks about testing, not supporting, so I suggest changing
"supported" to "tested".

> address@hidden
> +Interix 3.5 is not tested.

I suggest adding "Interix 6.1 is rarely tested, and requires suacomp 0.6.8 or 
later."; see
<http://lists.gnu.org/archive/html/bug-gnulib/2011-05/msg00324.html> and
<http://lists.gnu.org/archive/html/bug-tar/2011-05/msg00009.html>.

> +These operating systems are all supported in an unvirtualized environment.

I'd remove the above sentence, partly because of the "tested" versus "supported"
issue, partly because the sentence is redundant.

> +The following platforms are @emph{not} supported by Gnulib.  Even correct
> +patches for their support will not be applied.

Rather than just saying "no", it'll be helpful to give a few reasons why,
so that people don't write and ask "why?".  Also, there's no need for the @emph.
And it wouldn't hurt to add a "Please" here.  How about the following wording 
instead?
It tries to capture the essential (i.e., harsh :-) idea without being too 
off-putting.

  The following platforms are not supported by Gnulib.  The cost of supporting 
them
  would exceed the benefit because they're rarely used, or poorly documented,
  or have been supplanted by other platforms, or diverge too much from POSIX,
  or some combination of these and other factors.  Please don't bother sending
  us patches for them.