diff --git a/lib/ace/document.js b/lib/ace/document.js
index 99a76fc4..0e6258a4 100644
--- a/lib/ace/document.js
+++ b/lib/ace/document.js
@@ -38,7 +38,6 @@
 define(function(require, exports, module) {
 
 var oop = require("pilot/oop");
-var lang = require("pilot/lang");
 var EventEmitter = require("pilot/event_emitter").EventEmitter;
 var Range = require("ace/range").Range;
 
@@ -143,10 +142,21 @@ var Document = function(text) {
         }
     };
 
+    this.$clipPosition = function(position) {
+        var length = this.$lines.length;
+        if (position.row >= length) {
+            position.row = Math.max(0, length - 1);
+            position.column = this.getLine(length-1).length;
+        }
+        return position;        
+    }
+
     this.insert = function(position, text) {
         if (text.length == 0)
             return position;
-
+            
+        position = this.$clipPosition(position);
+            
         if (this.$lines.length <= 1) {
             this.$detectNewLine(text);
         }
@@ -160,7 +170,8 @@ var Document = function(text) {
             var end = this.insertInLine(position, text);
         }
         else {
-            this.insertInLine(position, newLines[0]);
+            var end = this.insertInLine(position, newLines[0]);
+            this.insertNewLine(end);
             if (newLines.length > 2)
                 this.insertLines(position.row+1, newLines.slice(1, newLines.length-1));
                 
@@ -173,24 +184,23 @@ var Document = function(text) {
     this.insertLines = function(row, lines) {
         if (lines.length == 0)
             return {row: row, column: 0};
-    
+            
         var args = [row, 0];
         args.push.apply(args, lines);
         this.$lines.splice.apply(this.$lines, args);
     
-        var range = new Range(row, 0, row + lines.length, 0);
+        var range = new Range(row, 0, row + lines.length - 1, 0);
         var delta = {
             action: "insertLines",
-            nl: this.getNewLineCharacter(),
             range: range,
             lines: lines
         };
-        this._dispatchEvent("changeDelta", { data: delta });    
+        this._dispatchEvent("change", { data: delta });    
         return range.end;
     },
     
     this.insertNewLine = function(position) {
-        console.log(position)
+        position = this.$clipPosition(position);
         var line = this.$lines[position.row] || "";
         this.$lines[position.row] = line.substring(0, position.column);
         this.$lines.splice(position.row + 1, 0, line.substring(position.column, line.length));
@@ -205,12 +215,15 @@ var Document = function(text) {
             range: Range.fromPoints(position, end),
             text: this.getNewLineCharacter()
         };
-        this._dispatchEvent("changeDelta", { data: delta });
+        this._dispatchEvent("change", { data: delta });
         
         return end;
     };
     
     this.insertInLine = function(position, text) {
+        if (text.length == 0)
+            return position;
+            
         var line = this.$lines[position.row] || "";
         this.$lines[position.row] = line.substring(0, position.column) + text
                 + line.substring(position.column);
@@ -225,18 +238,23 @@ var Document = function(text) {
             range: Range.fromPoints(position, end),
             text: text
         };
-        this._dispatchEvent("changeDelta", { data: delta });
+        this._dispatchEvent("change", { data: delta });
         
         return end;
     };
 
     this.remove = function(range) {
+        // clip to document
+        range.start = this.$clipPosition(range.start);
+        range.end = this.$clipPosition(range.end);
+
         if (range.isEmpty())
-            return range.start;
+            return;
+        
+        var firstRow = range.start.row;
+        var lastRow = range.end.row;
 
         if (range.isMultiLine()) {
-            var firstRow = range.start.row;
-            var lastRow = range.end.row;
             
             // TODO removeInLine can be optimized away!
             this.removeInLine(lastRow, 0, range.end.column);
@@ -246,13 +264,16 @@ var Document = function(text) {
             this.removeNewLine(range.start.row);
         }
         else {
-            this.removeInLine(range)
+            this.removeInLine(firstRow, range.start.column, range.end.column);
         }
     };
     
     this.removeInLine = function(row, startColumn, endColumn) {
+        if (startColumn == endColumn)
+            return;
+            
         var range = new Range(row, startColumn, row, endColumn);
-        var line = this.$lines[row];
+        var line = this.getLine(row);
         var removed = line.substring(startColumn, endColumn);
         var newLine = line.substring(0, startColumn) + line.substring(endColumn, line.length);
         this.$lines.splice(row, 1, newLine);
@@ -262,6 +283,7 @@ var Document = function(text) {
             range: range,
             text: removed
         };
+        this._dispatchEvent("change", { data: delta });
         return range.start;
     };
     
@@ -275,7 +297,7 @@ var Document = function(text) {
             nl: this.getNewLineCharacter(),
             lines: removed
         };
-        this._dispatchEvent("changeDelta", { data: delta });
+        this._dispatchEvent("change", { data: delta });
     };
     
     this.removeNewLine = function(row) {
@@ -292,7 +314,7 @@ var Document = function(text) {
             range: range,
             text: this.getNewLineCharacter()
         };
-        this._dispatchEvent("changeDelta", { data: delta });
+        this._dispatchEvent("change", { data: delta });
     };
     
     this.replace = function(range, text) {
@@ -316,6 +338,38 @@ var Document = function(text) {
     
         return end;
     };
+    
+    this.applyDeltas = function(deltas) {
+        for (var i=0; i<deltas.length; i++) {
+            var delta = deltas[i];
+            var range = delta.range;
+            
+            if (delta.action == "insertLines")
+                this.insertLines(range.start.row, delta.lines)
+            else if (delta.action == "insertText")
+                this.insert(range.start, delta.text)
+            else if (delta.action == "removeLines")
+                this.removeLines(range.start.row, range.end.row)
+            else if (delta.action == "removeText")
+                this.remove(range)
+        }        
+    };
+    
+    this.revertDeltas = function(deltas) {
+        for (var i=deltas.length-1; i>=0; i--) {
+            var delta = deltas[i];
+            var range = delta.range;
+            
+            if (delta.action == "insertLines")
+                this.removeLines(range.start.row, range.end.row)
+            else if (delta.action == "insertText")
+                this.remove(range)
+            else if (delta.action == "removeLines")
+                this.insertLines(range.start.row, delta.lines)
+            else if (delta.action == "removeText")
+                this.insert(range.start, delta.text)
+        }        
+    };
 
 }).call(Document.prototype);
 
diff --git a/lib/ace/test/document_test.js b/lib/ace/test/document_test.js
index 9076a7fd..5fc27ec3 100644
--- a/lib/ace/test/document_test.js
+++ b/lib/ace/test/document_test.js
@@ -42,9 +42,198 @@ var Document        = require("../document").Document,
         
 var Test = {
 
+    "test: insert text in line" : function() {
+        var doc = new Document(["12", "34"]);
+
+        var deltas = [];
+        doc.on("change", function(e) { deltas.push(e.data); });
+        
+        doc.insert({row: 0, column: 1}, "juhu");
+        assert.equal(doc.getValue(), ["1juhu2", "34"].join("\n"));
+        
+        var d = deltas.concat();        
+        doc.revertDeltas(d);
+        assert.equal(doc.getValue(), ["12", "34"].join("\n"));
+        
+        doc.applyDeltas(d);
+        assert.equal(doc.getValue(), ["1juhu2", "34"].join("\n"));
+    },
+    
+    "test: insert new line" : function() {
+        var doc = new Document(["12", "34"]);
+        
+        var deltas = [];
+        doc.on("change", function(e) { deltas.push(e.data); });
+
+        doc.insertNewLine({row: 0, column: 1});
+        assert.equal(doc.getValue(), ["1", "2", "34"].join("\n"));
+        
+        var d = deltas.concat();        
+        doc.revertDeltas(d);
+        assert.equal(doc.getValue(), ["12", "34"].join("\n"));
+        
+        doc.applyDeltas(d);
+        assert.equal(doc.getValue(), ["1", "2", "34"].join("\n"));
+    },
+    
+    "test: insert lines at the beginning" : function() {
+        var doc = new Document(["12", "34"]);
+        
+        var deltas = [];
+        doc.on("change", function(e) { deltas.push(e.data); });
+        
+        doc.insertLines(0, ["aa", "bb"]);
+        assert.equal(doc.getValue(), ["aa", "bb", "12", "34"].join("\n"));
+        
+        var d = deltas.concat();        
+        doc.revertDeltas(d);
+        assert.equal(doc.getValue(), ["12", "34"].join("\n"));
+        
+        doc.applyDeltas(d);
+        assert.equal(doc.getValue(), ["aa", "bb", "12", "34"].join("\n"));
+    },
+    
+    "test: insert lines at the end" : function() {
+        var doc = new Document(["12", "34"]);
+        
+        var deltas = [];
+        doc.on("change", function(e) { deltas.push(e.data); });
+        
+        doc.insertLines(2, ["aa", "bb"]);
+        assert.equal(doc.getValue(), ["12", "34", "aa", "bb"].join("\n"));
+    },
+    
+    "test: insert lines in the middle" : function() {
+        var doc = new Document(["12", "34"]);
+        
+        var deltas = [];
+        doc.on("change", function(e) { deltas.push(e.data); });
+        
+        doc.insertLines(1, ["aa", "bb"]);
+        assert.equal(doc.getValue(), ["12", "aa", "bb", "34"].join("\n"));
+        
+        var d = deltas.concat();        
+        doc.revertDeltas(d);
+        assert.equal(doc.getValue(), ["12", "34"].join("\n"));
+        
+        doc.applyDeltas(d);
+        assert.equal(doc.getValue(), ["12", "aa", "bb", "34"].join("\n"));
+    },
+    
+    "test: insert multi line string at the start" : function() {
+        var doc = new Document(["12", "34"]);
+        
+        var deltas = [];
+        doc.on("change", function(e) { deltas.push(e.data); });
+        
+        doc.insert({row: 0, column: 0}, "aa\nbb\ncc");
+        assert.equal(doc.getValue(), ["aa", "bb", "cc12", "34"].join("\n"));
+        
+        var d = deltas.concat();        
+        doc.revertDeltas(d);
+        assert.equal(doc.getValue(), ["12", "34"].join("\n"));
+        
+        doc.applyDeltas(d);
+        assert.equal(doc.getValue(), ["aa", "bb", "cc12", "34"].join("\n"));
+    },
+    
+    "test: insert multi line string at the end" : function() {
+        var doc = new Document(["12", "34"]);
+        
+        var deltas = [];
+        doc.on("change", function(e) { deltas.push(e.data); });
+        
+        doc.insert({row: 2, column: 0}, "aa\nbb\ncc");
+        assert.equal(doc.getValue(), ["12", "34aa", "bb", "cc"].join("\n"));
+        
+        var d = deltas.concat();        
+        doc.revertDeltas(d);
+        assert.equal(doc.getValue(), ["12", "34"].join("\n"));
+        
+        doc.applyDeltas(d);
+        assert.equal(doc.getValue(), ["12", "34aa", "bb", "cc"].join("\n"));
+    },
+    
+    "test: insert multi line string in the middle" : function() {
+        var doc = new Document(["12", "34"]);
+        
+        var deltas = [];
+        doc.on("change", function(e) { deltas.push(e.data); });
+        
+        doc.insert({row: 0, column: 1}, "aa\nbb\ncc");
+        assert.equal(doc.getValue(), ["1aa", "bb", "cc2", "34"].join("\n"));
+        
+        var d = deltas.concat();        
+        doc.revertDeltas(d);
+        assert.equal(doc.getValue(), ["12", "34"].join("\n"));
+        
+        doc.applyDeltas(d);
+        assert.equal(doc.getValue(), ["1aa", "bb", "cc2", "34"].join("\n"));
+    },
+    
+    "test: delete in line" : function() {
+        var doc = new Document(["1234", "5678"]);
+        
+        var deltas = [];
+        doc.on("change", function(e) { deltas.push(e.data); });
+        
+        doc.remove(new Range(0, 1, 0, 3));
+        assert.equal(doc.getValue(), ["14", "5678"].join("\n"));
+        
+        var d = deltas.concat();        
+        doc.revertDeltas(d);
+        assert.equal(doc.getValue(), ["1234", "5678"].join("\n"));
+        
+        doc.applyDeltas(d);
+        assert.equal(doc.getValue(), ["14", "5678"].join("\n"));
+    },
+
+    "test: delete new line" : function() {
+        var doc = new Document(["1234", "5678"]);
+        
+        var deltas = [];
+        doc.on("change", function(e) { deltas.push(e.data); });
+        
+        doc.remove(new Range(0, 4, 1, 0));
+        assert.equal(doc.getValue(), ["12345678"].join("\n"));
+        
+        var d = deltas.concat();        
+        doc.revertDeltas(d);
+        assert.equal(doc.getValue(), ["1234", "5678"].join("\n"));
+        
+        doc.applyDeltas(d);
+        assert.equal(doc.getValue(), ["12345678"].join("\n"));
+    },
+    
+    "test: delete multi line range line" : function() {
+        var doc = new Document(["1234", "5678", "abcd"]);
+        
+        var deltas = [];
+        doc.on("change", function(e) { deltas.push(e.data); });
+        
+        doc.remove(new Range(0, 2, 2, 2));
+        assert.equal(doc.getValue(), ["12cd"].join("\n"));
+        
+        var d = deltas.concat();        
+        doc.revertDeltas(d);
+        assert.equal(doc.getValue(), ["1234", "5678", "abcd"].join("\n"));
+        
+        doc.applyDeltas(d);
+        assert.equal(doc.getValue(), ["12cd"].join("\n"));
+    },
+    
+    "test: delete full lines" : function() {
+        var doc = new Document(["1234", "5678", "abcd"]);
+        
+        var deltas = [];
+        doc.on("change", function(e) { deltas.push(e.data); });
+        
+        doc.remove(new Range(1, 0, 3, 0));
+        assert.equal(doc.getValue(), ["1234", ""].join("\n"));
+    },
+
     "test: should handle unix style new lines" : function() {
         var doc = new Document(["1", "2", "3"]);
-        
         assert.equal(doc.getValue(), ["1", "2", "3"].join("\n"));
     },