and that is what we recommend you use. If you're already using or comfortable with
another Scheme implementation, though, there's no compelling reason to switch.
- <!-- Racket doesn't have R7RS-small, and won't anytime soon. :-( Perhaps prefer Chicken? -->
+ Another good Scheme implementation is Chicken. For our purposes, this is in some
+respects superior to Racket, and in other respects inferior.
+<!--
+Racket doesn't have R7RS-small, and won't anytime soon. :-(
+Also Chicken's library collection seems stronger, or at least better organized and maintained.
+Other R7RS-friendly: [Gauche](http://practical-scheme.net/gauche), [Chibi](https://code.google.com/p/chibi-scheme).
+-->
- Racket stands to Scheme in something like the relation Firefox stands to HTML.
+ Racket and Chicken stand to Scheme in something like the relation Firefox stands to HTML.
- (Wikipedia on [Lisp](http://en.wikipedia.org/wiki/Lisp_%28programming_language%29),
+ (Wikipedia on
+[Lisp](http://en.wikipedia.org/wiki/Lisp_%28programming_language%29),
[Scheme](http://en.wikipedia.org/wiki/Scheme_%28programming_language%29),
-and [Racket](http://en.wikipedia.org/wiki/Racket_%28programming_language%29).)
+[Racket](http://en.wikipedia.org/wiki/Racket_%28programming_language%29), and
+and [Chicken](http://en.wikipedia.org/wiki/CHICKEN_%28Scheme_implementation%29).)
* **Caml** is one of two major dialects of *ML*, which is another large
family of programming languages. Caml has only one active "implementation",
more generally; but you can assume that what we're talking about always works more
specifically in OCaml.
- (Wikipedia on [ML](http://en.wikipedia.org/wiki/ML_%28programming_language%29),
+ (Wikipedia on
+[ML](http://en.wikipedia.org/wiki/ML_%28programming_language%29),
[Caml](http://en.wikipedia.org/wiki/Caml),
and [OCaml](http://en.wikipedia.org/wiki/OCaml).)
familiar with one of them, it's generally not hard to move between it and the
other.
- (Wikipedia on [Haskell](http://en.wikipedia.org/wiki/Haskell_%28programming_language%29).)
+ Like Scheme, Haskell has a couple of different implementations. The
+dominant one, and the one we recommend you install, is called GHC, short
+for "Glasgow Haskell Compiler".
+
+ (Wikipedia on
+[Haskell](http://en.wikipedia.org/wiki/Haskell_%28programming_language%29) and
+[GHC](https://en.wikipedia.org/wiki/Glasgow_Haskell_Compiler).)
<a name=installing></a>
Another good Scheme implementation is [Chicken](http://www.call-cc.org). For our purposes, this is in some respects
superior to Racket, and in other respects inferior. If you have any issues with installing or using Racket, you could
try this out instead. You might even want to install both.
-
<!--
-Racket doesn't have R7RS-small, and won't anytime soon.
+Racket doesn't have R7RS-small, and won't anytime soon. :-(
+Also Chicken's library collection seems stronger, or at least better organized and maintained.
Other R7RS-friendly: [Gauche](http://practical-scheme.net/gauche), [Chibi](https://code.google.com/p/chibi-scheme).
-->