add ack to our sponsors

collects/meta/web/www/community.rkt

@@ -18,4 +18,13 @@
     @parlist[@strong{Development}
       @text{@git (also available on
             @a[href: "http://github.com/plt/racket/"]{GitHub})}
-      @text{@pre:installers and @pre:index{more}.}]})
+      @text{@pre:installers and @pre:index{more}.}]
+    @parlist[@strong{Support}
+      @text{Thanks to @a[href: "http://www.nsf.gov/"]{the NSF}, 
+                      @a[href: "http://www.darpa.mil/"]{DARPA}
+                      the Fund for the Improvement of Postsecondary Education (FIPSE) at the US Department of Education,
+                      the Exxon Foundation,
+                      CORD, partners of the Academy of Information Technology,
+                      Microsoft, and
+                      Google
+                      for their generous support.}]})