X-Git-Url: http://lambda.jimpryor.net/git/gitweb.cgi?p=lambda.git;a=blobdiff_plain;f=index.mdwn;h=6df8b02ec42c217008927b0619eec5edbd4a2fc7;hp=11bee2656244f0ba48420fcbfd7e7fc395e8812c;hb=0669c93a4922641c2c8c26ba90df1160a41eef90;hpb=b69d79536fa5452f2a3352ba96081dcb34297daa

diff --git a/index.mdwn b/index.mdwn
index 11bee265..6df8b02e 100644
--- a/index.mdwn
+++ b/index.mdwn
@@ -134,7 +134,7 @@ course is to enable you to make these tools your own; to have enough
 understanding of them to recognize them in use, use them yourself at least
 in simple ways, and to be able to read more about them when appropriate.
 
-[[More about the topics and larger themes of the course| overview]]
+[[More about the topics and larger themes of the course|overview]]
 
 
 ## Who Can Participate? ##
@@ -202,13 +202,20 @@ the operating system differently. One major implementation is called Racket,
 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
+[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",
@@ -216,13 +223,13 @@ OCaml, developed by the INRIA academic group in France. Sometimes we may refer t
 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),
-[Caml](http://en.wikipedia.org/wiki/Caml),
-and [OCaml](http://en.wikipedia.org/wiki/OCaml).)
+    (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).)
 
 
-*   Those of you with some programming background may have encountered a third
-prominent functional programming language, **Haskell**. This is also used a
+*   **Haskell** is also used a
 lot in the academic contexts we'll be working through. Its surface syntax
 differs from Caml, and there are various important things one can do in
 each of Haskell and Caml that one can't (or can't as easily) do in the
@@ -230,7 +237,13 @@ other. But these languages also have *a lot* in common, and if you're
 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>