diff --git a/base/ape/hood.hoon b/base/ape/hood.hoon
index e6aa536525..ce5d3318c2 100644
--- a/base/ape/hood.hoon
+++ b/base/ape/hood.hoon
@@ -1,5 +1,5 @@
- ::                                                      ::  ::
-::::  /hoon/hood/ape                               ::  ::
+::                                                      ::  ::
+::::  /hoon/hood/ape                                    ::  ::
   ::                                                    ::  ::
 /?  314                                                 ::  zuse version
 /+  sole, talk, helm, kiln, drum                        ::  libraries
@@ -53,7 +53,7 @@
 ++  coup-kiln-spam                                      ::
   |=  [way=wire saw=(unit tang)]
   ~?  ?=(^ saw)  [%kiln-spam-lame u.saw]
-  [~ +>] 
+  [~ +>]
 ::
 ++  coup-drum-phat  (wrap take-coup-phat):from-drum
 ++  diff-sole-effect-drum-phat  (wrap diff-sole-effect-phat):from-drum
diff --git a/base/mar/hoon.hoon b/base/mar/hoon.hoon
index 115abcebd9..93a8e5356f 100644
--- a/base/mar/hoon.hoon
+++ b/base/mar/hoon.hoon
@@ -8,8 +8,34 @@
 ++  grow                                                ::  convert to
   |%
   ++  mime  `^mime`[/text/hoon (taco own)]              ::  convert to %mime
-  ++  elem  ;div:(pre:"{(trip own)}")                   ::  convert to %html
-  ++  hymn  ;html:(head:title:"Source" "+{elem}")
+  ++  elem                                              ::  convert to %html
+    ;div:pre(urb_codemirror ""):"{(trip own)}"
+    :: =+  gen-id="src-{<`@ui`(mug own)>}"
+    :: ;div
+    ::   ;textarea(id "{gen-id}"):"{(trip own)}"
+    ::   ;script:"""
+    ::           CodeMirror.fromTextArea(
+    ::             window[{<gen-id>}],
+    ::             \{lineNumbers:true, readOnly:true}
+    ::           )
+    ::           """
+    :: ==
+  ++  hymn
+    :: ;html:(head:title:"Source" "+{elem}")
+    ;html
+      ;head
+        ;title:"Source"
+        ;script@"//cdnjs.cloudflare.com/ajax/libs/codemirror/4.3.0/codemirror.js";
+        ;script@"/{(trip &2:%)}/lib/syntax/hoon.js";
+        ;link(rel "stylesheet", href "//cdnjs.cloudflare.com/ajax/libs/".
+          "codemirror/4.3.0/codemirror.min.css");
+        ;link/"/{(trip &2:%)}/lib/syntax/codemirror.css"(rel "stylesheet");
+      == 
+      ;body
+        ;textarea#src:"{(trip own)}"
+        ;script:'CodeMirror.fromTextArea(src, {lineNumbers:true, readOnly:true})'
+      ==
+    ==
   ++  txt
     (lore (cat 3 own '\0a'))
   --