diff --git a/lib/ace/edit_session.js b/lib/ace/edit_session.js
index e9e2a66a..c0c3c6ad 100644
--- a/lib/ace/edit_session.js
+++ b/lib/ace/edit_session.js
@@ -198,6 +198,41 @@ var EditSession = function(text, mode) {
         this._dispatchEvent("changeBreakpoint", {});
     };
 
+    this.getBreakpoints = function() {
+        return this.$breakpoints;
+    };
+
+    /**
+     * Error: 
+     *  {
+     *    row: 12,
+     *    column: 2, //can be undefined
+     *    text: "Missing argument",
+     *    type: "error" // or "warning" or "info"
+     *  }
+     */
+    this.setAnnotations = function(annotations) {
+        this.$annotations = [];
+        for (var i=0; i<annotations.length; i++) {
+            var annotation = annotations[i];
+            var row = annotation.row;
+            if (this.$annotations[row])
+                this.$annotations[row].push(annotation);
+            else
+                this.$annotations[row] = [annotation];
+        }
+        this._dispatchEvent("changeAnnotation", {});
+    };
+
+    this.getAnnotations = function() {
+        return this.$annotations;
+    };
+    
+    this.clearAnnotations = function() {
+        this.$annotations = [];
+        this._dispatchEvent("changeAnnotation", {});
+    };
+
     this.$detectNewLine = function(text) {
         var match = text.match(/^.*?(\r?\n)/m);
         if (match) {
diff --git a/lib/ace/editor.js b/lib/ace/editor.js
index 807d1d2a..6aeeee4b 100644
--- a/lib/ace/editor.js
+++ b/lib/ace/editor.js
@@ -126,6 +126,7 @@ var Editor =function(renderer, session) {
             this.session.removeEventListener("changeMode", this.$onDocumentModeChange);
             this.session.removeEventListener("changeTabSize", this.$onDocumentChangeTabSize);
             this.session.removeEventListener("changeBreakpoint", this.$onDocumentChangeBreakpoint);
+            this.session.removeEventListener("changeAnnotation", this.$onDocumentChangeAnnotation);
 
             var selection = this.session.getSelection();
             selection.removeEventListener("changeCursor", this.$onCursorChange);
@@ -148,6 +149,9 @@ var Editor =function(renderer, session) {
 
         this.$onDocumentChangeBreakpoint = this.onDocumentChangeBreakpoint.bind(this);
         this.session.addEventListener("changeBreakpoint", this.$onDocumentChangeBreakpoint);
+        
+        this.$onDocumentChangeAnnotation = this.onDocumentChangeAnnotation.bind(this);
+        this.session.addEventListener("changeAnnotation", this.$onDocumentChangeAnnotation);
 
         this.selection = session.getSelection();
         this.$desiredColumn = 0;
@@ -165,6 +169,7 @@ var Editor =function(renderer, session) {
         this.onCursorChange();
         this.onSelectionChange();
         this.onDocumentChangeBreakpoint();
+        this.onDocumentChangeAnnotation();
         this.renderer.scrollToRow(session.getScrollTopRow());
         this.renderer.updateFull();
     };
@@ -289,6 +294,10 @@ var Editor =function(renderer, session) {
         this.renderer.setBreakpoints(this.session.getBreakpoints());
     };
 
+    this.onDocumentChangeAnnotation = function() {
+        this.renderer.setAnnotations(this.session.getAnnotations());
+    };
+
     this.onDocumentModeChange = function() {
         var mode = this.session.getMode();
         if (this.mode == mode)
diff --git a/lib/ace/layer/gutter.js b/lib/ace/layer/gutter.js
index aa3e5e7c..13c85bad 100644
--- a/lib/ace/layer/gutter.js
+++ b/lib/ace/layer/gutter.js
@@ -45,6 +45,7 @@ var Gutter = function(parentEl) {
     parentEl.appendChild(this.element);
 
     this.$breakpoints = [];
+    this.$annotations = [];
     this.$decorations = [];
 };
 
@@ -57,22 +58,49 @@ var Gutter = function(parentEl) {
     }
     
     this.removeGutterDecoration = function(row, className){
-        this.$decorations[row] = 
-            this.$decorations[row].replace(" ace_" + className, "");
-    }
+        this.$decorations[row] = this.$decorations[row].replace(" ace_" + className, "");
+    };
 
     this.setBreakpoints = function(rows) {
         this.$breakpoints = rows.concat();
     };
 
+    this.setAnnotations = function(annotations) {
+        // iterate over sparse array
+        this.$annotations = [];
+        for (var row in annotations) {
+            var rowInfo = this.$annotations[row] = {
+                text: []
+            };
+            var rowAnnotations = annotations[row];
+            for (var i=0; i<rowAnnotations.length; i++) {
+                var annotation = rowAnnotations[i];
+                rowInfo.text.push(annotation.text.replace(/"/g, "&quot;").replace(/'/g, "&rsquo;").replace(/</, "&lt;"));
+                var type = annotation.type;
+                if (type == "error")
+                    rowInfo.className = "ace_error";
+                else if (type == "warning" && rowInfo.className != "ace_error")
+                    rowInfo.className = "ace_warning";
+                else if (type == "info" && (!rowInfo.className))
+                    rowInfo.className = "ace_info";
+            }
+        }
+    };
+
     this.update = function(config) {
         this.$config = config;
 
         var html = [];
         for ( var i = config.firstRow; i <= config.lastRow; i++) {
+            var annotation = this.$annotations[i] || {
+                className: "",
+                text: []
+            };
             html.push("<div class='ace_gutter-cell",
                 this.$decorations[i] || "",
-                this.$breakpoints[i] ? " ace_breakpoint" : "",
+                this.$breakpoints[i] ? " ace_breakpoint " : " ",
+                annotation.className,
+                "' title='", annotation.text.join("\n"),
                 "' style='height:", config.lineHeight, "px;'>", (i+1), "</div>");
             html.push("</div>");
         }
diff --git a/lib/ace/virtual_renderer.js b/lib/ace/virtual_renderer.js
index 687085fa..affce7fb 100644
--- a/lib/ace/virtual_renderer.js
+++ b/lib/ace/virtual_renderer.js
@@ -474,6 +474,11 @@ var VirtualRenderer = function(container, theme) {
         this.$loop.schedule(this.CHANGE_GUTTER);
     };
 
+    this.setAnnotations = function(annotations) {
+        this.$gutterLayer.setAnnotations(annotations);
+        this.$loop.schedule(this.CHANGE_GUTTER);
+    };
+
     this.updateCursor = function(position, overwrite) {
         this.$cursorLayer.setCursor(position, overwrite);
         this.$loop.schedule(this.CHANGE_CURSOR);