diff --git a/res/extensions/spellCheck.js b/res/extensions/spellCheck.js
index e5d95ae3..d92ebc63 100644
--- a/res/extensions/spellCheck.js
+++ b/res/extensions/spellCheck.js
@@ -1,6 +1,7 @@
 define([
     "jquery",
     "underscore",
+    "crel",
     "utils",
     "classes/Extension",
     "typo-js",
@@ -8,43 +9,139 @@ define([
     "text!dictionaries/en_US.dic",
     "text!dictionaries/en_US.aff",
     "text!html/tocSettingsBlock.html",
-    ], function($, _, utils, Extension, Typo, XRegExp, dic, aff, tocSettingsBlockHTML) {
+    ], function($, _, crel, utils, Extension, Typo, XRegExp, dic, aff, tocSettingsBlockHTML) {
 
     var spellCheck = new Extension("spellCheck", "Spell Check", true);
     spellCheck.settingsBlock = tocSettingsBlockHTML;
 
     var aceEditor = undefined;
+    var timeoutId = undefined;
+    var dictionary = new Typo('en_US', aff, dic);
+    var wordRegExp = XRegExp('\\p{L}+', 'g');
+    var markers = [];
+    var rowIndex = 0;
+
+    function check() {
+        var tokenOffset = 0,
+            processedTokens = 0;
+        var Range = require('ace/range').Range;
+
+        function checkToken(token) {
+            if (token.checked === undefined && !/code|code_block|reference|markup\.underline/.test(token.type)) {
+                token.value.replace(wordRegExp, function(word, offset) {
+                    if (!dictionary.check(word)) {
+                        offset += tokenOffset;
+                        var range = new Range(rowIndex, offset, rowIndex, offset + word.length);
+                        var markerId = aceEditor.session.addMarker(range, "misspelled", "typo", true);
+                        var marker = aceEditor.session.getMarkers(true)[markerId];
+                        console.log(marker);
+                        markers.push(marker);
+                    }
+                });
+                processedTokens++;
+            }
+            token.checked = true;
+            tokenOffset += token.value.length;
+        }
+        var rowCount = aceEditor.session.getDocument().getLength();
+        for (; rowIndex < rowCount; rowIndex++) {
+            var tokens = aceEditor.session.getTokens(rowIndex);
+            tokenOffset = 0;
+            _.each(tokens, checkToken);
+            if (processedTokens > 5) {
+                timeoutId = setTimeout(check, 20);
+                return;
+            }
+        }
+    }
+
+    function stop() {
+        timeoutId && clearTimeout(timeoutId);
+        timeoutId = undefined;
+    }
+
+    function start() {
+        var savedMarkers = [];
+        console.log(rowIndex);
+        _.each(markers, function(marker) {
+            if (marker.range.start.row < rowIndex) {
+                savedMarkers.push(marker);
+            }
+            else {
+                aceEditor.session.removeMarker(marker.id);
+            }
+        });
+        markers = savedMarkers;
+        timeoutId = setTimeout(check, 700);
+    }
+
+    var fileOpen = false;
+    spellCheck.onFileClose = function() {
+        stop();
+        fileOpen = false;
+    };
+
+    spellCheck.onFileOpen = function() {
+        fileOpen = true;
+        rowIndex = 0;
+        stop();
+        start();
+    };
+
+/*
+    var dropdownElt = undefined;
+    var $dropdownElt = undefined;
+    var liEltTmpl = [
+        '<li>',
+        '   <a href="#">',
+        '       <%= suggestion %>',
+        '   </a>',
+        '</li>'
+    ].join('');
+    */
     spellCheck.onAceCreated = function(aceEditorParam) {
         aceEditor = aceEditorParam;
-    };
-
-    var context = undefined;
-    spellCheck.onFileClose = function() {
-        if (context !== undefined) {
-            _.each(context.markers, function(marker) {
-                aceEditor.session.removeMarker(marker);
-            });
-        }
-        context = undefined;
-    };
-
-    var dictionary = new Typo('en_US', aff, dic);
-    spellCheck.onFileOpen = function() {
-        context = {
-            markers: []
-        };
-        var Range = require('ace/range').Range;
-        var lines = aceEditor.session.getDocument().getAllLines();
-        _.each(lines, function(line, index) {
-            line.replace(XRegExp('\\p{L}+', 'g'), function(word, offset) {
-                if (!dictionary.check(word)) {
-                    console.log(word);
-                    var range = new Range(index, offset, index, offset + word.length);
-                    context.markers[index] = aceEditor.session.addMarker(range, "misspelled", "typo", true);
+        aceEditor.session.on('change', function(e) {
+            if (fileOpen === true) {
+                var modifiedRowIndex = e.data.range.start.row;
+                if (modifiedRowIndex < rowIndex) {
+                    rowIndex = modifiedRowIndex;
+                }
+                stop();
+                start();
+            }
+        });
+        /*
+        aceEditor.on("click", function(ev) {
+            var screenCoordinates = aceEditor.renderer.pixelToScreenCoordinates(ev.x, ev.y);
+            var documentPosition = aceEditor.session.screenToDocumentPosition(screenCoordinates.row, screenCoordinates.column);
+            _.each(markers, function(marker) {
+                if (marker.range.contains(documentPosition.row, documentPosition.column)) {
+                    var word = aceEditor.session.getTextRange(marker.range);
+                    var suggestions = dictionary.suggest(word.toLowerCase());
+                    console.log(word, suggestions);
+                    var liListHtml = _.reduce(suggestions, function(result, suggestion) {
+                        return result + _.template(liEltTmpl, {
+                            suggestion: suggestion,
+                        });
+                    }, '');
+                    dropdownElt.innerHTML = liListHtml;
+                    $(dropdownElt).dropdown('toggle');
                 }
             });
         });
     };
 
+    spellCheck.onReady = function() {
+        dropdownElt = crel('ul', {
+            class: 'dropdown-menu dropdown-spell-checker'
+        });
+        document.querySelector('.ui-layout-resizer-north').appendChild(crel('div', crel('div', {
+            'data-toggle': 'dropdown'
+        }), dropdownElt));
+        $dropdownElt = $(dropdownElt).dropdown();
+        */
+    };
+
     return spellCheck;
 });
\ No newline at end of file
diff --git a/res/styles/main.less b/res/styles/main.less
index df6f971a..efc7e74b 100644
--- a/res/styles/main.less
+++ b/res/styles/main.less
@@ -1025,7 +1025,12 @@ ul,ol {
 		color: @primary-color-lighter;
 	}
 	
-	.ace_marker-layer .misspelled { position: absolute; z-index: -2; border-bottom: 1px dotted red; margin-bottom: -1px; }
+	.ace_marker-layer .misspelled {
+	    position: absolute;
+	    z-index: -2;
+	    border-bottom: 1px dotted red;
+	    margin-bottom: -1px;
+	}
 }
 
 .ace_search {