You can scratch RoPS of that list: anything that it does do, it not only does it slowly, but improperly. To make matters worse, 'paid' version is no better.
I had a discussion with Manfred von Thun (you know, the gentleman who created Joy) about this while I was working on a language that was similar to postscript & joy. He was interested in the design aspects we were discussing, but was hesitant about the PS aspects I was using. I should think that the real reason that PostScript is so slow is that the graphics rely upon someone who should have really optimised some the workings out of their source file...
Just my $0.02 (or 0.01 GBP)

On 10/3/06, Jack Johnson <knapjack@gmail.com> wrote:
On 10/3/06, Charles Forsyth <forsyth@terzarima.net> wrote:
> out of idle interest, why has there never been a replacement?
> is it really that hard?

That's a great question.  I Googled for some leads:

"Saffron includes an all-Java PostScript(r) interpreter"
http://www.dynalivery.com/customersupport/Saffron_FAQs/SaffronInfo.html

"The RoPS interpreter is a Microsoft Windows implementation of the
PostScript programming language interpreter"
http://www.rops.org/

There is some interesting detail stuff here that I'd want to re-read
if I were going to write an interpreter from scratch:
http://www.anastigmatix.net/postscript/direct.html

This might also make for a good jumping-off point:
http://serl.cs.colorado.edu/~arcadia/Software/tps.html

...but from the looks of it, maybe it would be easier to "fix"
ghostscript by making it faster/slimmer/etc.  I wonder if it runs
better on some architectures than others?  If so, sounds like a good
job for a cpu server.

-Jack



--
If work and leisure are soon to be subordinated to this one utopian principle -- absolute busyness -- then utopia and melancholy will come to coincide: an age without conflict will dawn, perpetually busy -- and without consciousness.

-- Günter Grass