Prothon is switching to the .NET platform

Guido van Rossum guido at
Fri Aug 6 07:12:45 CEST 2004

Hi Mark,

It was a pleasure to meet you at VanPy, and I was sorry that I had to
leave in the middle of your talk (I had a plane to catch and David had
scared me about delays).

I was pleasantly surprised in hearing your architecture for the
Prothon engine -- it sounded like a fresh look at implementing a
runtime for a Python-like language, and several features (like the
locking strategy) sounded like I should be paying attention to them
for the Python 3000 interpreter.

So now I'm a bit disappointed to hear that you're giving all that up
and switching to the CLR.  I understand your desire to have a large
library available (though most of that library will be class-based,
which may require you to bring classes back in through the back door).
But in practical terms, it makes Prothon a lot less accessible in the
years to come.

I recall that installing .NET on Windows took me half a day.  Maybe
it's gotten better, but I sure can't believe they've shrunk it.  Mono
gives you theoretical support on Linux, but it's even more of a
questionable proposition to actually run it (and its set of supported
runtime libraries has only a small intersection with what's available
in .NET).  Basically, telling people "here's my language, it's a 2 MB
download, and oh, BTW, you also need to install the 200 MB runtime
over there" isn't exactly encouraging people to play with your
language.  Even for apps written in Java this is a significant barrier
-- I have several copies of Java on my hard drive because every
significant application written in Java ends up needing a different
JVM version.  And the JVM I downloaded last year is probably too old
to run this year's crop of bleeding edge Java apps.  Availability of
the CLR is a lot less than Java.

I'm also surprised because you admit to being a poor language designer
(although you picked a great example :-).  I assumed this to mean that
you're having more fun implementing the runtime.  But if you're not
doing it for the language design, and now you're giving up on the
runtime, what's left?

Hoping your website was hacked or it was practical joke,

--Guido van Rossum (home page:

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