Racket has been rocking my world lately.

In particular, I love that you can arbitrarily define (or redefine) patterns for the match construct using macros.

It leads to some damn elegant code:

http://matt.might.net/articles/red-black-delete/

http://matt.might.net/articles/parsing-with-derivatives/

I played around (rather ineffectually) with David's Haskell code, back when the whole "Yacc is Dead" stuff was here, and I still tend to believe that Haskell results in less code when laziness is involved :)

That said, I think I really like define/fix

Summary for the impatient:

- A completely new GUI and drawing layer. Replacing 200,000 lines of C++, Xt, Win32, and Carbon with about 30,000 lines of Racket that builds on Gtk, Win32, Cocoa, Cairo, and Pango. Nice. - Web server changed semantics - Scribble documents can now hold any image - Module dependency tools

Racket seems to be really neat with support for features like JIT and futures (which have been around before 5.1).

The other day I tried a simple benchmark (nothing elaborate - just fib) and found it to be significantly faster than Python. Unfortunately I don't have the numbers right now.

Does anyone have any experience to share regarding the use of Racket in a production app?

benchmark game comparison: http://shootout.alioth.debian.org/u32/benchmark.php?test=all...

Yes, Racket looks to be almost an order of magnitude faster on most of the benchmarks.

In case I'm not the only person who thought “What’s Racket?”, it’s the language formerly known as PLT Scheme. It was renamed last year.

And, to everyone's surprise, the wiki page has not been marked for deletion yet. Doubleplus good.

Back using Racket after a long hiatus. Racket I never should have left you. There are but two languages I'll use. Racket and Scala.

Ditto, only for Scheme in general (I used Chicken the last time around). I chose Racket this time for all the "batteries included" stuff.

I've never shipped anything written in Scheme, but my excursions into it have always left me a wiser programmer.