Some web page tweaks.

* The main page's title appears in search results, so use "The Racket
  Language" instead of "Racket".  Additional minor tweaks to a few more
  titles to make them presentable as search results.

* Add a `#:description' keyword to make it easy to add it to pages.  Add
  such texts to the main page, downloads, community, learning, people,
  and mailing list pages.

* Add a <meta name="robots" content="NOODP" /> to the front page, to
  avoid getting the ODP (dmoz) blurb, hopefully the new and improved
  description(s) will be used instead.  (If not, this should be
  reverted.)

collects/meta/web/common/layout.rkt

@@ -67,7 +67,8 @@
                ;; can be #f (default), 'full: full page (and no div),
                ;; otherwise, a css width
                #:width [width #f]
-               #:extra-headers [headers #f]
+               #:description [description #f] ; for a meta tag
+               #:extra-headers [extra-headers #f]
                #:extra-body-attrs [body-attrs #f]
                #:resources resources ; see below
                #:referrer [referrer
@@ -75,24 +76,29 @@
                              (a href: url (if (null? more) linktitle more)))]
                ;; will be used instead of `this' to determine navbar highlights
                #:part-of [part-of #f]
-               content)
+               content0)
   (define (page)
-    (let* ([head    (resources 'head wintitle headers)]
+    (define desc
-           [navbar  (resources 'navbar (or part-of this))]
+      (and description (meta name: 'description content: description)))
-           [content (case width
+    (define headers
-                      [(full) content]
+      (if (and extra-headers desc)
-                      [(#f) (div class: 'bodycontent content)]
+        (list desc "\n" extra-headers)
-                      [else (div class: 'bodycontent
+        (or desc extra-headers)))
-                                 style: @list{width: @|width|@";"}
+    (define head   (resources 'head wintitle headers))
-                                 content)])]
+    (define navbar (resources 'navbar (or part-of this)))
-           [content @list{@navbar
+    (define content
-                          @content}])
+      (list navbar "\n"
+            (case width
+              [(full) content0]
+              [(#f) (div class: 'bodycontent content0)]
+              [else (div class: 'bodycontent style: @list{width: @|width|@";"}
+                      content0)])))
     @xhtml{@||
            @head
            @(if body-attrs
               (apply body `(,@body-attrs ,content))
               (body content))
-             @||}))
+           @||})
   (define this (and (not html-only?)
                     (resource/referrer (get-path 'plain id file "html" dir)
                                        (file-writer output-xml page)

collects/meta/web/download/index.rkt

@@ -12,7 +12,11 @@
 
 (provide index)
 (define index
-  @page[#:link-title "Downloads" #:part-of 'download]{
+  @page[#:link-title "Downloads" #:part-of 'download
+        #:description
+        @'{Download Racket, a modern dialect of Lisp/Scheme.  @;
+           Available for Windows, Mac, Linux, and other Unix platforms.  @;
+           Includes the DrRacket IDE.}]{
     @div[style: "float: right;"]{@download-button}
     Use these links to browse the download directories directly:
     @ul{@li{Current @a[href: `(,installers "/recent")]{installers}

collects/meta/web/minis/lists.rkt

@@ -21,6 +21,8 @@
 
 (define lists
   @page[#:title "Mailing Lists" #:file "" #:part-of 'community
+        #:description
+        @'{Racket mailing lists for users, developers, announcements, and more.}
     (define (list-cells what) (map (λ (r) (r what)) list-renderers))
     ]{
     @p{This is the Racket mailing list server.  We have several public mailing

collects/meta/web/www/community.rkt

@@ -7,7 +7,10 @@
 
 (provide community)
 (define community
-  @page[#:part-of 'community]{
+  @page[#:window-title "Racket Community Resources" #:part-of 'community
+        #:description
+        @'{Racket-related community resources: mailing lists, IRC channel, @;
+           resources for developers, RacketCon, blog, and more.}]{
     @mailing-lists-quick
     @irc-quick
     @parlist[@strong{PLT Scheme Inc.}

collects/meta/web/www/index.rkt

@@ -260,8 +260,14 @@
 
 (provide index)
 (define index
-  (page #:link-title "About" #:window-title "Racket"
+  (page #:link-title "About" #:window-title "The Racket Language"
-        #:extra-headers @list{@meta[name: 'description content: blurb]
+        #:description
+        @'{Racket is a modern programming language in the Lisp/Scheme family, @;
+           suitable for a wide range of applications.  @;
+           Racket provides a rich language extension API, the DrRacket @;
+           integrated development environment, and many batteries-included @;
+           libraries.}
+        #:extra-headers @list{@meta[name: "robots" content: "NOODP"]
                               @(lazy more.css)}
     @div[class: 'leftpane]{
       @span[style: "font-size: large; font-weight: bold;"]{Racket}

collects/meta/web/www/learning.rkt

@@ -4,7 +4,11 @@
 
 (provide learning)
 (define learning
-  @page[#:part-of 'learning]{
+  @page[#:window-title "Racket Learning" #:part-of 'learning
+        #:description
+        '@{Racket-related learning resources.  Introductions to Racket, @;
+           the Racket Guide, Computer Science textbooks that use Racket, @;
+           outreach programs, and graduate studies.}]{
     @parlist[@strong{Resources for Learning}
       (apply parlist @text{Documentation for getting started:} intros)
       @text{@-htdp — a textbook for introductory programming, but also

collects/meta/web/www/people.rkt

@@ -95,7 +95,8 @@
 
 (provide people)
 (define people
-  @page[#:part-of 'community]{
+  @page[#:window-title "Racket People: The PLT Group" #:part-of 'community
+        #:description "PLT: the group that is the Racket development team."]{
     @p{“PLT” refers to the group that is the core of the Racket development
        team.  PLT consists of numerous people distributed across several
        different universities in the USA: