diff --git a/src/server/MainFastCGI.hs b/src/server/MainFastCGI.hs
index d678c1579..230e09b00 100644
--- a/src/server/MainFastCGI.hs
+++ b/src/server/MainFastCGI.hs
@@ -11,6 +11,7 @@ import qualified Codec.Binary.UTF8.String as UTF8 (encodeString)
 import Control.Exception
 import Control.Monad
 import Data.Dynamic
+import qualified Data.Map as Map
 import Data.Maybe
 
 
@@ -31,12 +32,13 @@ cgiMain :: PGF -> CGI CGIResult
 cgiMain pgf =
     do path <- pathInfo
        json <- case path of
-         "/parse"      -> return (doParse pgf) `ap` getText `ap` getCat `ap` getFrom
-         "/linearize"  -> return (doLinearize pgf) `ap` getTree `ap` getTo
-         "/translate"  -> return (doTranslate pgf) `ap` getText `ap` getCat `ap` getFrom `ap` getTo
-         "/categories" -> return $ doCategories pgf
-         "/languages"  -> return $ doLanguages pgf
-         _             -> throwCGIError 404 "Not Found" ["Resource not found: " ++ path]
+         "/parse"          -> return (doParse pgf) `ap` getText `ap` getCat `ap` getFrom
+         "/complete"       -> return (doComplete pgf) `ap` getText `ap` getCat `ap` getFrom
+         "/linearize"      -> return (doLinearize pgf) `ap` getTree `ap` getTo
+         "/translate"      -> return (doTranslate pgf) `ap` getText `ap` getCat `ap` getFrom `ap` getTo
+         "/categories"     -> return $ doCategories pgf
+         "/languages"      -> return $ doLanguages pgf
+         _                 -> throwCGIError 404 "Not Found" ["Resource not found: " ++ path]
        outputJSON json
   where
     getText :: CGI String
@@ -80,6 +82,9 @@ doParse :: PGF -> String -> Maybe PGF.Category -> Maybe PGF.Language -> JSValue
 doParse pgf input mcat mfrom = showJSON $ toJSObject $
      [(from, map PGF.showTree trees) | (from,trees) <- parse' pgf input mcat mfrom]
 
+doComplete :: PGF -> String -> Maybe PGF.Category -> Maybe PGF.Language -> JSValue
+doComplete pgf input mcat mfrom = showJSON $ toJSObject $ complete' pgf input mcat mfrom
+
 doLinearize :: PGF -> PGF.Tree -> Maybe PGF.Language -> JSValue
 doLinearize pgf tree mto = showJSON $ toJSObject $ linearize' pgf mto tree
 
@@ -96,10 +101,24 @@ doCategories pgf = showJSON (PGF.categories pgf)
 
 parse' :: PGF -> String -> Maybe PGF.Category -> Maybe PGF.Language -> [(PGF.Language,[PGF.Tree])]
 parse' pgf input mcat mfrom = 
-    case mfrom of
-      Nothing   -> PGF.parseAllLang pgf cat input
-      Just from -> [(from, PGF.parse pgf from cat input)]
-  where cat = fromMaybe (PGF.startCat pgf) mcat
+   [(from,ts) | from <- froms, PGF.canParse pgf from, let ts = PGF.parse pgf from cat input, not (null ts)]
+  where froms = maybe (PGF.languages pgf) (:[]) mfrom
+        cat = fromMaybe (PGF.startCat pgf) mcat
+
+complete' :: PGF -> String -> Maybe PGF.Category -> Maybe PGF.Language -> [(PGF.Language,[String])]
+complete' pgf input mcat mfrom = 
+   [(from,ss) | from <- froms, PGF.canParse pgf from, let ss = complete pgf from cat input, not (null ss)]
+  where froms = maybe (PGF.languages pgf) (:[]) mfrom
+        cat = fromMaybe (PGF.startCat pgf) mcat
+
+complete :: PGF -> PGF.Language -> PGF.Category -> String -> [String]
+complete pgf from cat input = 
+         let ws = words input
+             prefix = "" -- FIXME
+             state0 = PGF.initState pgf from cat
+             state = foldl PGF.nextState state0 ws
+             compls = PGF.getCompletions state prefix
+          in Map.keys compls
 
 linearize' :: PGF -> Maybe PGF.Language -> PGF.Tree -> [(PGF.Language,String)]
 linearize' pgf mto tree = 
diff --git a/src/server/gf-client.html b/src/server/gf-client.html
index 4516d7e1e..a3558e25c 100644
--- a/src/server/gf-client.html
+++ b/src/server/gf-client.html
@@ -13,10 +13,11 @@
         var input = document.getElementById('inputText').value;
         var fromLang = document.getElementById('fromLang').value;
         var toLang = document.getElementById('toLang').value;
-        var output = document.getElementById('output');
+        var output = document.getElementById('translation');
+
         var callback = function(translation) {
-                         removeChildren(output);
-                         output.appendChild(formatTranslation(translation));
+                          clearTranslation();
+                          output.appendChild(formatTranslation(translation));
                        };
         gf.translate(input, fromLang, toLang, '', callback);
       }
@@ -32,23 +33,55 @@
         }
       }
 
+      function updateCompletion() {
+        var input = document.getElementById('inputText').value;
+        var fromLang = document.getElementById('fromLang').value;
+        var completions = document.getElementById('completion');
+
+//        if (document.getElementById('enableCompletion').checked) {
+          var callback = function(output) {
+            clearCompletion();
+            completions.appendChild(formatCompletions(output));
+          };
+          gf.complete(input, fromLang, '', callback);
+//        }
+      }
+
+      function update() {
+        updateCompletion();
+        updateTranslation();
+      }
+
+      function clearTranslation() {
+        var output = document.getElementById('translation');
+        removeChildren(output);
+      }
+
+      function clearCompletion() {
+        var completions = document.getElementById('completion');
+        removeChildren(completions);
+      }
+
       function initialize() {
-        gf.getLanguages(populateLangs);
+        gf.languages(populateLangs);
       }
     </script>
     <title>AJAX GF Translator</title>
   </head>
   <body onload="initialize()">
-    <form id="translate" onsubmit="updateTranslation(); return false;">
-      <p>
-        <input type="text" name="inputText" id="inputText" value="this cheese is warm" size="50" />
-      </p>
-      <p>
-        From: <select name="fromLang" id="fromLang" onchange="updateTranslation()"><option value="">Any language</option></select>
-        To: <select name="toLang" id="toLang" onchange="updateTranslation()"><option value="">All languages</option></select>
-        <input type="submit" value="Translate" />
-      </p>
-    </form>
-    <div id="output"></div>
+    <div id="translator">
+      <form onsubmit="update(); return false;">
+        <p>
+          <input type="text" id="inputText" value="this cheese is warm" size="50" onkeyup="update()"/>
+        </p>
+        <p>
+          <label>From: <select id="fromLang" onchange="update()"><option value="">Any language</option></select></label>
+          <label>To: <select id="toLang" onchange="update()"><option value="">All languages</option></select></label>
+          <input type="submit" value="Translate" />
+        </p>
+      </form>
+      <div id="completion"></div>
+      <div id="translation"></div>
+    </div>
   </body>
 </html>
diff --git a/src/server/gf-server-jsapi.js b/src/server/gf-server-jsapi.js
index 9a2096532..dfa50c2f7 100644
--- a/src/server/gf-server-jsapi.js
+++ b/src/server/gf-server-jsapi.js
@@ -4,7 +4,11 @@ gf.translate = function (input,from,to,cat,callback) {
   gf.httpGetText("gf.fcgi/translate?input="+escape(input)+"&from="+escape(from)+"&to="+escape(to)+"&cat="+escape(cat), function (output) { callback(gf.readJSON(output)); });
 };
 
-gf.getLanguages = function (callback) {
+gf.complete = function (input,from,cat,callback) {
+  gf.httpGetText("gf.fcgi/complete?input="+escape(input)+"&from="+escape(from)+"&cat="+escape(cat), function (output) { callback(gf.readJSON(output)); });
+};
+
+gf.languages = function (callback) {
     gf.httpGetText("gf.fcgi/languages", function (output) { callback(gf.readJSON(output)); });
 };
 
diff --git a/src/server/gf-server.cabal b/src/server/gf-server.cabal
index f6104e481..67935e491 100644
--- a/src/server/gf-server.cabal
+++ b/src/server/gf-server.cabal
@@ -11,6 +11,7 @@ executable gf.fcgi
                  old-time,
                  unix,
                  directory,
+                 containers,
                  gf,
                  cgi,
                  fastcgi,
diff --git a/src/server/translator.css b/src/server/translator.css
index f7f771927..d4fb7be1f 100644
--- a/src/server/translator.css
+++ b/src/server/translator.css
@@ -1,10 +1,12 @@
 body {
   color: black;
   background-color: white;
+  font-family: sans-serif;
 }
 
 dl {
-
+  margin: 0;
+  padding: 0;
 }
 
 dt {
@@ -17,6 +19,29 @@ dl dd {
   padding: 0;
 }
 
+ul {
+  margin: 0;
+  padding: 0;
+}
+
+li {
+  list-style-type: none;
+  margin: 0;
+  padding: 0;
+}
+
+/* Translator widget */
+
+#translator {
+
+}
+
+/* Translations */
+
+#translation {
+  clear: both;   
+}
+
 dl.fromLang dt {
   display: none;
 }
@@ -32,23 +57,33 @@ dl.toLang dt {
   display: block;
   float: left;
   width: 5em;
+  font-size: 80%;
+  padding: 1px 0;
 }
 
-
 dl.toLang dd {
   border-width: 0 0 1px 0;
   border-style: solid;
   border-color: #c0c0c0;
+  padding: 0.2em 0;
 }
 
+/* Completions */
 
-ul {
-  margin: 0;
-  padding: 0;
+#completion {
+   font-size: 80%;
+   color: #c0c0c0;
+   white-space: nowrap;
+   width: 100%;
+   overflow: hidden;
+}
+
+#completion dt {
+  display: none;   
+}
+
+#completion li {
+  display: inline;
+  padding: 0 0.1em;
 }
 
-li {
-  list-style-type: none;
-  margin: 0;
-  padding: 0;
-}
\ No newline at end of file
diff --git a/src/server/translator.js b/src/server/translator.js
index 31da04290..96acd52d2 100644
--- a/src/server/translator.js
+++ b/src/server/translator.js
@@ -17,6 +17,18 @@ function formatTranslation (outputs) {
   return dl1;
 }
 
+function formatCompletions (compls) {
+  var dl = document.createElement("dl");
+  for (var fromLang in compls) {
+    var ul = document.createElement("ul");
+    for (var i in compls[fromLang]) {
+      addItem(ul, document.createTextNode(compls[fromLang][i]));
+    }
+    addDefinition(dl, document.createTextNode(fromLang), ul);
+  }
+  return dl;
+}
+
 /* DOM utilities for specific tags */
 
 function addDefinition (dl, t, d) {