diff --git a/dotfiles.mk b/dotfiles.mk
index 30d4afd..2ec263d 100644
--- a/dotfiles.mk
+++ b/dotfiles.mk
@@ -1,9 +1,13 @@
 EMACS = /usr/bin/emacs
+SCHEME_IMPLEMENTATION = guile
 
 define tangle =
+	echo $(SCHEME_IMPLEMENTATION)
 	@echo -e "\e[35mOBT\e[0m" $<
 	@$(EMACS) -batch \
         -eval "(package-initialize)" \
         -load ob-tangle \
+        -eval "(setq sh-make-vars-local nil)" \
+        -eval "(setq geiser-default-implementation '$(SCHEME_IMPLEMENTATION))" \
         -eval "(org-babel-tangle-file \"$<\" \"$(notdir $@)\" \"$(1)\")"
 endef
diff --git a/mowedline/.config/mowedline/init.org b/mowedline/.config/mowedline/init.org
index 623353e..b89e225 100644
--- a/mowedline/.config/mowedline/init.org
+++ b/mowedline/.config/mowedline/init.org
@@ -1,3 +1,5 @@
+#+TITLE: Mowedline init
+
 Load the =matchable= module so I can use =match-lambda=.
 
 #+BEGIN_SRC scheme
@@ -11,74 +13,127 @@ Set the default font and color to something nicer.
   (text-widget-color "#ededed")
 #+END_SRC
 
-This formatter will parse the herbstluftwm tag status line, which
-looks like this:
-
-#+BEGIN_EXAMPLE
-  #1  -2  :3  :4  :5  .6  .7  .8  .9
-#+END_EXAMPLE
-
-And turn it into something more useful. The symbols before the tag
-names (numbers) have the following meaning:
-
-- =#= :: This tag is currently active.
-- =-= :: This tag is visible on another monitor.
-- =:= :: This tag isn't displayed, but has windows on it.
-- =.= :: This tag isn't displayed and is empty.
-- =!= :: This tag has an urgent window on it.
-
-First the tag line has to be split into separate parts. Each tag
-status/name pair is split by a tab character and each status is only
-one character. So I split the whole string on tabs and then make a
-list out of each individual part, for easy access to the status
-character. So we end up with something like:
-
-#+BEGIN_EXAMPLE
-  ((#\# #\1) (#\- #\2) (#\: #\3) ...)
-#+END_EXAMPLE
+Define a convenience function to check if a formatter's argument is
+not some text.
 
 #+BEGIN_SRC scheme
-  (define (split-tag-list str)
-    (map string->list (string-split str "\t")))
+  (define (not-text? text)
+    (or (null? text) (and (not (pair? text)) (string-null? text))))
 #+END_SRC
 
-Next we turn each part into something practical for display in
-mowedline.
+Define a convenience function that adds spaces around its argument if
+its argument is text.
 
 #+BEGIN_SRC scheme
-  (define tag-display
-    (match-lambda
-     ((#\# . name-list)
-      (list '(color "#ececec" font "FontAwesome-10" "")
-            (string-append " " (list->string name-list) " ")))
-     ((#\- . _) '((color "#bfbfbf" font "FontAwesome-10" "") " "))
-     ((#\: . _) '((color "#969696" font "FontAwesome-10" "") " "))
-     ((#\! . _) '((color "#a85454" font "FontAwesome-10" "") " "))
-     (_ '())))
-
-  (define (tag-list-display tag-list)
-    (map tag-display tag-list))
+  (define (text-maybe-pad-both text)
+    (if (not-text? text)
+        text
+        (list " " text " ")))
 #+END_SRC
 
-Finally, bring it all together in a function that can be used as a
-mowedline text formatter.
+Define a convenience function to add a Font Awesome icon to a widget.
 
 #+BEGIN_SRC scheme
-  (define (tag-list-formatter text)
-    (tag-list-display (split-tag-list text)))
+  (define (add-fa-icon icon)
+    (lambda (text)
+      (if (not-text? text)
+          text
+          (list (list 'font "FontAwesome-10"
+                      (string-append " " icon " "))
+                text))))
 #+END_SRC
 
-Create a mowedline window, put it at the bottom.
+* Tag list
 
-#+BEGIN_SRC scheme
-  (window #:position 'bottom
-          #:width 1843
-          #:margin-bottom 15
-          #:margin-left 46
-          #:margin-right 15
-          #:background 'transparent
+  This formatter will parse the herbstluftwm tag status line, which
+  looks like this:
 
-          (widget:text #:name "taglist" #:format tag-list-formatter)
-          (widget:spacer #:flex 1)
-          (widget:clock))
-#+END_SRC
+  #+BEGIN_EXAMPLE
+    #1  -2  :3  :4  :5  .6  .7  .8  .9
+  #+END_EXAMPLE
+
+  And turn it into something more useful. The symbols before the tag
+  names (numbers) have the following meaning:
+
+  - =#= :: This tag is currently active.
+  - =-= :: This tag is visible on another monitor.
+  - =:= :: This tag isn't displayed, but has windows on it.
+  - =.= :: This tag isn't displayed and is empty.
+  - =!= :: This tag has an urgent window on it.
+
+  First the tag line has to be split into separate parts. Each tag
+  status/name pair is split by a tab character and each status is only
+  one character. So I split the whole string on tabs and then make a
+  list out of each individual part, for easy access to the status
+  character. So we end up with something like:
+
+  #+BEGIN_EXAMPLE
+    ((#\# #\1) (#\- #\2) (#\: #\3) ...)
+  #+END_EXAMPLE
+
+  #+BEGIN_SRC scheme
+    (define (split-tag-list str)
+      (map string->list (string-split str "\t")))
+  #+END_SRC
+
+  Next we turn each part into something practical for display in
+  mowedline.
+
+  #+BEGIN_SRC scheme
+    (define tag-display
+      (match-lambda
+       ((#\# . name-list)
+        (list '(color "#ececec" font "FontAwesome-10" "")
+              (string-append " " (list->string name-list) " ")))
+       ((#\- . _) '((color "#bfbfbf" font "FontAwesome-10" "") " "))
+       ((#\: . _) '((color "#969696" font "FontAwesome-10" "") " "))
+       ((#\! . _) '((color "#a85454" font "FontAwesome-10" "") " "))
+       (_ '())))
+
+    (define (tag-list-display tag-list)
+      (map tag-display tag-list))
+  #+END_SRC
+
+  Finally, bring it all together in a function that can be used as a
+  mowedline text formatter.
+
+  #+BEGIN_SRC scheme
+    (define (tag-list-formatter text)
+      (tag-list-display (split-tag-list text)))
+  #+END_SRC
+
+  Define the widget to be used in the window.
+
+  #+BEGIN_SRC scheme
+    (define taglist-widget
+      (widget:text #:name "taglist" #:format tag-list-formatter))
+  #+END_SRC
+
+* Email
+
+  Define a widget to show email notifications in.
+
+  #+BEGIN_SRC scheme
+    (define email-widget
+      (widget:text
+       #:name "email"
+       #:format (compose text-maybe-pad-both (add-fa-icon ""))))
+  #+END_SRC
+
+* The window
+
+  Create a mowedline window, put it at the bottom.
+
+  #+BEGIN_SRC scheme
+    (window #:position 'bottom
+            #:width 1843
+            #:margin-bottom 15
+            #:margin-left 46
+            #:margin-right 15
+            #:background 'transparent
+
+            taglist-widget
+            (widget:spacer #:flex 1)
+            email-widget
+            (widget:clock))
+  #+END_SRC
diff --git a/mowedline/GNUmakefile b/mowedline/GNUmakefile
index e393a0b..ee829e6 100644
--- a/mowedline/GNUmakefile
+++ b/mowedline/GNUmakefile
@@ -2,5 +2,6 @@ include ../dotfiles.mk
 
 all: .config/mowedline/init.scm
 
+%.scm: SCHEME_IMPLEMENTATION = chicken
 %.scm: %.org
 	$(call tangle,scheme)