Try using pandoc?

web/src/Within/DBMemorial/Post.hs

@@ -8,6 +8,7 @@ import           Database.SQLite.Simple.FromRow
 import           Text.Blaze.Html5               ((!))
 import qualified Text.Blaze.Html5               as H
 import qualified Text.Blaze.Html5.Attributes    as A
+import           Text.Pandoc
 
 data Post = Post
           { id       :: Int
@@ -26,4 +27,9 @@ render post = do
     H.div ! A.class_ "card blue-grey darken-1" $ do
       H.div ! A.class_ "card-content white-text" $ do
         H.span ! A.class_ "card-title" $ H.toHtml $ unpack (author post)
-        H.p $ H.toHtml $ unpack (markdown post)
+
+        state <- case readTextile def (unpack $ body post) of
+              Right v -> return v
+              Left err -> error (show err)
+
+        H.p $ writeHtml def state

web/time-wasting-thread-memorial.cabal

@@ -65,6 +65,8 @@ executable time-wasting-thread-memorial
                      , blaze-markup >=0.7.0.2
                      , wai-middleware-static >=0.7.0.1
                      , wai-extra >=1.3.0
+                     , pandoc >=1.15.0.6
+                     , mtl >=2.2.1
 
   -- Directories containing source files.
   hs-source-dirs:      src