

PLT Scheme 4.0 released - stassats
http://blog.plt-scheme.org/2008/06/plt-scheme-version-4.html

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delackner
I have no experience with lisp or scheme, but reading the new tutorial on
their website was such a beautiful introduction to programming, and then I
looked at the source code for the tutorial and was blown away at the level of
simplicity and sophistication they have achieved.

So why have I never heard of PLT Scheme? Why isn't it popular?

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vegashacker
I think it's probably the premiere Scheme implementation. Arc is built in it
(you may have heard only of MzScheme, but that's in the PLT family). I happen
to be using it for my startup.

As far as various Schemes go, I'd say it's very popular.

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jimbokun
Stumbled upon this while checking out the blog:

[http://www.youtube.com/watch?v=vgQO_kHl39g&fmt=18](http://www.youtube.com/watch?v=vgQO_kHl39g&fmt=18)

Very impressive. The features in Dr. Scheme make for an excellent teaching
environment, but look like they would work well for a working programmer,
also.

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Tichy
What do you think about the set-car! thing? Why not just use Erlang instead?

~~~
j2d2
Can you elaborate?

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Tichy
Maybe I misunderstood, but it seems to me that without set-car!, Scheme
becomes more like Erlang in respect to "unchangeable variables" (don't
remember the proper term right now).

I had recently evaluated Erlang but found some things very difficult to
achieve. For a contrieved problem, how do you program an effective algorithm
to calculate prime numbers in Erlang?

So I felt quite good about the destructive operators of Scheme. If they are
now wanted anymore, I might reconsider using Erlang.

~~~
jcl
My understanding of the situation is that the PLT people had some
optimizations they could do if lists were immutable, and they noticed that
there were very few places in their code where they mutated lists. So they
decided to just make lists immutable and see who complained. And it turns out
few other people were actually mutating lists, so they kept the optimization.

PLT Scheme still has other mutable data structures that can be used instead of
lists, though; I don't know if this is the case for Erlang.

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gills
Wow, they made the site much cleaner as well.

