diff --git a/build_support/boot.js b/build_support/boot.js
index e311cebc..f61e91d6 100644
--- a/build_support/boot.js
+++ b/build_support/boot.js
@@ -51,20 +51,20 @@ var ace = {
         var env = require("pilot/environment").create();
         var catalog = require("pilot/plugin_manager").catalog;
         catalog.startupPlugins({ env: env }).then(function() {
-            var Document = require("ace/document").Document;
+            var EditSession = require("ace/edit_session").EditSession;
             var JavaScriptMode = require("ace/mode/javascript").Mode;
             var UndoManager = require("ace/undomanager").UndoManager;
             var Editor = require("ace/editor").Editor;
             var Renderer = require("ace/virtual_renderer").VirtualRenderer;
             var theme = require("ace/theme/textmate");
 
-            var doc = new Document(el.innerHTML);
+            var doc = new EditSession(el.innerHTML);
             el.innerHTML = '';
             doc.setMode(new JavaScriptMode());
             doc.setUndoManager(new UndoManager());
             env.document = doc;
             env.editor = new Editor(new Renderer(el, theme));
-            env.editor.setDocument(doc);
+            env.editor.setSession(doc);
             env.editor.resize();
             window.addEventListener("resize", function() {
                 env.editor.resize();
diff --git a/demo/startup.js b/demo/startup.js
index e3a9e1a3..b62e79e3 100644
--- a/demo/startup.js
+++ b/demo/startup.js
@@ -102,7 +102,7 @@ exports.launch = function(env) {
 
     var modeEl = document.getElementById("mode");
     function setMode() {
-        env.editor.getDocument().setMode(modes[modeEl.value] || modes.text);
+        env.editor.getSession().setMode(modes[modeEl.value] || modes.text);
     }
     modeEl.onchange = setMode;
     setMode();
@@ -120,7 +120,7 @@ exports.launch = function(env) {
     var docEl = document.getElementById("doc");
     function onDocChange() {
         var doc = docs[docEl.value];
-        env.editor.setDocument(doc);
+        env.editor.setSession(doc);
     
         var mode = doc.getMode();
         if (mode instanceof JavaScriptMode) {
@@ -240,7 +240,7 @@ exports.launch = function(env) {
                 env.editor.onTextInput(reader.result);
 
                 modeEl.value = mode;
-                env.editor.getDocument().setMode(modes[mode]);
+                env.editor.getSession().setMode(modes[mode]);
             };
             reader.readAsText(file);
         }
diff --git a/lib/ace/edit_session.js b/lib/ace/edit_session.js
index c022dd04..ce959e57 100644
--- a/lib/ace/edit_session.js
+++ b/lib/ace/edit_session.js
@@ -77,6 +77,10 @@ var EditSession = function(text, mode) {
         doc.on("change", this.onChange.bind(this));
     };
     
+    this.getDocument = function() {
+        return this.doc;
+    };
+    
     this.onChange = function(e) {
         var delta = e.data;
         this.$modified = true;
diff --git a/lib/ace/editor.js b/lib/ace/editor.js
index 927711ce..4055d2b2 100644
--- a/lib/ace/editor.js
+++ b/lib/ace/editor.js
@@ -48,7 +48,7 @@ var BackgroundTokenizer = require("ace/background_tokenizer").BackgroundTokenize
 var Range = require("ace/range").Range;
 var EventEmitter = require("pilot/event_emitter").EventEmitter;
 
-var Editor =function(renderer, doc) {
+var Editor =function(renderer, session) {
     var container = renderer.getContainerElement();
     this.container = container;
     this.renderer = renderer;
@@ -78,7 +78,7 @@ var Editor =function(renderer, doc) {
         wrap: true
     });
 
-    this.setDocument(doc || new EditSession(""));
+    this.setSession(session || new EditSession(""));
     this.focus();
 };
 
@@ -118,38 +118,38 @@ var Editor =function(renderer, doc) {
         return this.keyBinding.getKeyboardHandler();
     }
 
-    this.setDocument = function(doc) {
-        if (this.doc == doc) return;
+    this.setSession = function(session) {
+        if (this.session == session) return;
 
-        if (this.doc) {
-            this.doc.removeEventListener("change", this.$onDocumentChange);
-            this.doc.removeEventListener("changeMode", this.$onDocumentModeChange);
-            this.doc.removeEventListener("changeTabSize", this.$onDocumentChangeTabSize);
-            this.doc.removeEventListener("changeBreakpoint", this.$onDocumentChangeBreakpoint);
+        if (this.session) {
+            this.session.removeEventListener("change", this.$onDocumentChange);
+            this.session.removeEventListener("changeMode", this.$onDocumentModeChange);
+            this.session.removeEventListener("changeTabSize", this.$onDocumentChangeTabSize);
+            this.session.removeEventListener("changeBreakpoint", this.$onDocumentChangeBreakpoint);
 
-            var selection = this.doc.getSelection();
+            var selection = this.session.getSelection();
             selection.removeEventListener("changeCursor", this.$onCursorChange);
             selection.removeEventListener("changeSelection", this.$onSelectionChange);
 
-            this.doc.setScrollTopRow(this.renderer.getScrollTopRow());
+            this.session.setScrollTopRow(this.renderer.getScrollTopRow());
         }
 
-        this.doc = doc;
+        this.session = session;
 
         this.$onDocumentChange = this.onDocumentChange.bind(this);
-        doc.addEventListener("change", this.$onDocumentChange);
-        this.renderer.setDocument(doc);
+        session.addEventListener("change", this.$onDocumentChange);
+        this.renderer.setSession(session);
 
         this.$onDocumentModeChange = this.onDocumentModeChange.bind(this);
-        doc.addEventListener("changeMode", this.$onDocumentModeChange);
+        session.addEventListener("changeMode", this.$onDocumentModeChange);
 
         this.$onDocumentChangeTabSize = this.renderer.updateText.bind(this.renderer);
-        doc.addEventListener("changeTabSize", this.$onDocumentChangeTabSize);
+        session.addEventListener("changeTabSize", this.$onDocumentChangeTabSize);
 
         this.$onDocumentChangeBreakpoint = this.onDocumentChangeBreakpoint.bind(this);
-        this.doc.addEventListener("changeBreakpoint", this.$onDocumentChangeBreakpoint);
+        this.session.addEventListener("changeBreakpoint", this.$onDocumentChangeBreakpoint);
 
-        this.selection = doc.getSelection();
+        this.selection = session.getSelection();
         this.$desiredColumn = 0;
 
         this.$onCursorChange = this.onCursorChange.bind(this);
@@ -159,18 +159,18 @@ var Editor =function(renderer, doc) {
         this.selection.addEventListener("changeSelection", this.$onSelectionChange);
 
         this.onDocumentModeChange();
-        this.bgTokenizer.setDocument(doc);
+        this.bgTokenizer.setDocument(session.getDocument());
         this.bgTokenizer.start(0);
 
         this.onCursorChange();
         this.onSelectionChange();
         this.onDocumentChangeBreakpoint();
-        this.renderer.scrollToRow(doc.getScrollTopRow());
+        this.renderer.scrollToRow(session.getScrollTopRow());
         this.renderer.updateFull();
     };
 
-    this.getDocument = function() {
-        return this.doc;
+    this.getSession = function() {
+        return this.session;
     };
 
     this.getSelection = function() {
@@ -201,7 +201,7 @@ var Editor =function(renderer, doc) {
         setTimeout(function() {
             self.$highlightPending = false;
 
-            var pos = self.doc.findMatchingBracket(self.getCursorPosition());
+            var pos = self.session.findMatchingBracket(self.getCursorPosition());
             if (pos) {
                 var range = new Range(pos.row, pos.column, pos.row, pos.column+1);
                 self.$bracketHighlight = self.renderer.addMarker(range, "ace_bracket");
@@ -280,11 +280,11 @@ var Editor =function(renderer, doc) {
     };
 
     this.onDocumentChangeBreakpoint = function() {
-        this.renderer.setBreakpoints(this.doc.getBreakpoints());
+        this.renderer.setBreakpoints(this.session.getBreakpoints());
     };
 
     this.onDocumentModeChange = function() {
-        var mode = this.doc.getMode();
+        var mode = this.session.getMode();
         if (this.mode == mode)
             return;
 
@@ -308,7 +308,7 @@ var Editor =function(renderer, doc) {
         var pageY = event.getDocumentY(e);
 
         var pos = this.renderer.screenToTextCoordinates(pageX, pageY);
-        pos.row = Math.max(0, Math.min(pos.row, this.doc.getLength()-1));
+        pos.row = Math.max(0, Math.min(pos.row, this.session.getLength()-1));
 
         if (event.getButton(e) != 0) {
             if (this.selection.isEmpty()) {
@@ -345,7 +345,7 @@ var Editor =function(renderer, doc) {
                 return;
 
             var cursor = self.renderer.screenToTextCoordinates(mousePageX, mousePageY);
-            cursor.row = Math.max(0, Math.min(cursor.row, self.doc.getLength()-1));
+            cursor.row = Math.max(0, Math.min(cursor.row, self.session.getLength()-1));
 
             if (self.$clickSelection) {
                 if (self.$clickSelection.contains(cursor.row, cursor.column)) {
@@ -394,7 +394,7 @@ var Editor =function(renderer, doc) {
 
     this.getCopyText = function() {
         if (!this.selection.isEmpty()) {
-            return this.doc.getTextRange(this.getSelectionRange());
+            return this.session.getTextRange(this.getSelectionRange());
         }
         else {
             return "";
@@ -406,7 +406,7 @@ var Editor =function(renderer, doc) {
             return;
 
         if (!this.selection.isEmpty()) {
-            this.moveCursorToPosition(this.doc.remove(this.getSelectionRange()));
+            this.moveCursorToPosition(this.session.remove(this.getSelectionRange()));
             this.clearSelection();
         }
     };
@@ -416,28 +416,28 @@ var Editor =function(renderer, doc) {
             return;
 
         var cursor = this.getCursorPosition();
-        text = text.replace("\t", this.doc.getTabString());
+        text = text.replace("\t", this.session.getTabString());
 
         // remove selected text
         if (!this.selection.isEmpty()) {
-            var cursor = this.doc.remove(this.getSelectionRange());
+            var cursor = this.session.remove(this.getSelectionRange());
             this.clearSelection();
         } else if (this.$overwrite){
             var range = new Range.fromPoints(cursor, cursor);
             range.end.column += text.length;
-            this.doc.remove(range);
+            this.session.remove(range);
         }
 
         this.clearSelection();
 
         var lineState     = this.bgTokenizer.getState(cursor.row);
-        var shouldOutdent = this.mode.checkOutdent(lineState, this.doc.getLine(cursor.row), text);
-        var line          = this.doc.getLine(cursor.row);
-        var lineIndent    = this.mode.getNextLineIndent(lineState, line.slice(0, cursor.column), this.doc.getTabString());
-        var end           = this.doc.insert(cursor, text);
+        var shouldOutdent = this.mode.checkOutdent(lineState, this.session.getLine(cursor.row), text);
+        var line          = this.session.getLine(cursor.row);
+        var lineIndent    = this.mode.getNextLineIndent(lineState, line.slice(0, cursor.column), this.session.getTabString());
+        var end           = this.session.insert(cursor, text);
 
         /* TODO: This shortcut is somehow broken
-        if (!shouldOutdent && line != this.doc.getLine(row) && text != "\n") {
+        if (!shouldOutdent && line != this.session.getLine(row) && text != "\n") {
             this.moveCursorToPosition(end);
             this.renderer.scrollCursorIntoView();
             return;
@@ -447,13 +447,13 @@ var Editor =function(renderer, doc) {
         var lineState = this.bgTokenizer.getState(cursor.row);
         // multi line insert
         if (cursor.row !== end.row) {
-            var size        = this.doc.getTabSize(),
+            var size        = this.session.getTabSize(),
                 minIndent   = Number.MAX_VALUE;
 
             for (var row = cursor.row + 1; row <= end.row; ++row) {
                 var indent = 0;
 
-                line = this.doc.getLine(row);
+                line = this.session.getLine(row);
                 for (var i = 0; i < line.length; ++i)
                     if (line.charAt(i) == '\t')
                         indent += size;
@@ -468,18 +468,18 @@ var Editor =function(renderer, doc) {
             for (var row = cursor.row + 1; row <= end.row; ++row) {
                 var outdent = minIndent;
 
-                line = this.doc.getLine(row);
+                line = this.session.getLine(row);
                 for (var i = 0; i < line.length && outdent > 0; ++i)
                     if (line.charAt(i) == '\t')
                         outdent -= size;
                     else if (line.charAt(i) == ' ')
                         outdent -= 1;
-                this.doc.replace(new Range(row, 0, row, line.length), line.substr(i));
+                this.session.replace(new Range(row, 0, row, line.length), line.substr(i));
             }
-            end.column += this.doc.indentRows(cursor.row + 1, end.row, lineIndent);
+            end.column += this.session.indentRows(cursor.row + 1, end.row, lineIndent);
         } else {
             if (shouldOutdent) {
-                end.column += this.mode.autoOutdent(lineState, this.doc, cursor.row);
+                end.column += this.mode.autoOutdent(lineState, this.session, cursor.row);
             }
         }
 
@@ -595,7 +595,7 @@ var Editor =function(renderer, doc) {
         if (this.selection.isEmpty()) {
             this.selection.selectRight();
         }
-        this.moveCursorToPosition(this.doc.remove(this.getSelectionRange()));
+        this.moveCursorToPosition(this.session.remove(this.getSelectionRange()));
         this.clearSelection();
     };
 
@@ -606,7 +606,7 @@ var Editor =function(renderer, doc) {
         if (this.selection.isEmpty())
             this.selection.selectLeft();
 
-        this.moveCursorToPosition(this.doc.remove(this.getSelectionRange()));
+        this.moveCursorToPosition(this.session.remove(this.getSelectionRange()));
         this.clearSelection();
     };
 
@@ -614,21 +614,21 @@ var Editor =function(renderer, doc) {
         if (this.$readOnly)
             return;
 
-        var doc     = this.doc,
-            range   = this.getSelectionRange();
+        var session = this.session;
+        var range = this.getSelectionRange();
 
         if (range.start.row < range.end.row || range.start.column < range.end.column) {
             var rows = this.$getSelectedRows();
-            var count = doc.indentRows(rows.first, rows.last, "\t");
+            var count = session.indentRows(rows.first, rows.last, "\t");
 
             this.selection.shiftSelection(count);
         } else {
             var indentString;
 
-            if (this.doc.getUseSoftTabs()) {
-                var size        = doc.getTabSize(),
+            if (this.session.getUseSoftTabs()) {
+                var size        = session.getTabSize(),
                     position    = this.getCursorPosition(),
-                    column      = doc.documentToScreenColumn(position.row, position.column),
+                    column      = session.documentToScreenColumn(position.row, position.column),
                     count       = (size - column % size);
 
                 indentString = lang.stringRepeat(" ", count);
@@ -642,8 +642,8 @@ var Editor =function(renderer, doc) {
         if (this.$readOnly)
             return;
 
-        var selection = this.doc.getSelection();
-        var range = this.doc.outdentRows(selection.getRange());
+        var selection = this.session.getSelection();
+        var range = this.session.outdentRows(selection.getRange());
 
         selection.setSelectionRange(range, selection.isBackwards());
         this.$updateDesiredColumn();
@@ -655,7 +655,7 @@ var Editor =function(renderer, doc) {
 
         var state = this.bgTokenizer.getState(this.getCursorPosition().row);
         var rows = this.$getSelectedRows()
-        var addedColumns = this.mode.toggleCommentLines(state, this.doc, rows.first, rows.last);
+        var addedColumns = this.mode.toggleCommentLines(state, this.session, rows.first, rows.last);
         this.selection.shiftSelection(addedColumns);
     };
 
@@ -667,7 +667,7 @@ var Editor =function(renderer, doc) {
         this.selection.setSelectionAnchor(rows.last+1, 0);
         this.selection.selectTo(rows.first, 0);
 
-        this.doc.remove(this.getSelectionRange());
+        this.session.remove(this.getSelectionRange());
         this.clearSelection();
     };
 
@@ -676,7 +676,7 @@ var Editor =function(renderer, doc) {
             return;
 
         this.$moveLines(function(firstRow, lastRow) {
-            return this.doc.moveLinesDown(firstRow, lastRow);
+            return this.session.moveLinesDown(firstRow, lastRow);
         });
     };
 
@@ -685,7 +685,7 @@ var Editor =function(renderer, doc) {
             return;
 
         this.$moveLines(function(firstRow, lastRow) {
-            return this.doc.moveLinesUp(firstRow, lastRow);
+            return this.session.moveLinesUp(firstRow, lastRow);
         });
     };
 
@@ -694,7 +694,7 @@ var Editor =function(renderer, doc) {
             return;
 
         this.$moveLines(function(firstRow, lastRow) {
-            this.doc.duplicateLines(firstRow, lastRow);
+            this.session.duplicateLines(firstRow, lastRow);
             return 0;
         });
     };
@@ -704,7 +704,7 @@ var Editor =function(renderer, doc) {
             return;
 
         this.$moveLines(function(firstRow, lastRow) {
-            return this.doc.duplicateLines(firstRow, lastRow);
+            return this.session.duplicateLines(firstRow, lastRow);
         });
     };
 
@@ -798,7 +798,7 @@ var Editor =function(renderer, doc) {
     this.gotoPageDown = function() {
         var row     = this.getPageDownRow(),
             column  = Math.min(this.getCursorPosition().column,
-                               this.doc.getLine(row).length);
+                               this.session.getLine(row).length);
 
         this.scrollToRow(row);
         this.getSelection().moveCursorTo(row, column);
@@ -807,7 +807,7 @@ var Editor =function(renderer, doc) {
     this.gotoPageUp = function() {
        var  row     = this.getPageUpRow(),
             column  = Math.min(this.getCursorPosition().column,
-                               this.doc.getLine(row).length);
+                               this.session.getLine(row).length);
 
        this.scrollToRow(row);
        this.getSelection().moveCursorTo(row, column);
@@ -874,7 +874,7 @@ var Editor =function(renderer, doc) {
 
         if (this.$desiredColumn) {
             var cursor = this.getCursorPosition();
-            var column = this.doc.screenToDocumentColumn(cursor.row, this.$desiredColumn);
+            var column = this.session.screenToDocumentColumn(cursor.row, this.$desiredColumn);
             this.selection.moveCursorTo(cursor.row, column);
         }
     };
@@ -885,14 +885,14 @@ var Editor =function(renderer, doc) {
 
         if (this.$desiredColumn) {
             var cursor = this.getCursorPosition();
-            var column = this.doc.screenToDocumentColumn(cursor.row, this.$desiredColumn);
+            var column = this.session.screenToDocumentColumn(cursor.row, this.$desiredColumn);
             this.selection.moveCursorTo(cursor.row, column);
         }
     };
 
     this.$updateDesiredColumn = function() {
         var cursor = this.getCursorPosition();
-        this.$desiredColumn = this.doc.documentToScreenColumn(cursor.row, cursor.column);
+        this.$desiredColumn = this.session.documentToScreenColumn(cursor.row, cursor.column);
     };
 
     this.navigateLeft = function(times) {
@@ -957,7 +957,7 @@ var Editor =function(renderer, doc) {
         if (options)
             this.$search.set(options);
 
-        var range = this.$search.find(this.doc);
+        var range = this.$search.find(this.session);
         this.$tryReplace(range, replacement);
         if (range !== null)
             this.selection.setSelectionRange(range);
@@ -969,7 +969,7 @@ var Editor =function(renderer, doc) {
             this.$search.set(options);
         }
 
-        var ranges = this.$search.findAll(this.doc);
+        var ranges = this.$search.findAll(this.session);
         if (!ranges.length)
             return;
 
@@ -984,10 +984,10 @@ var Editor =function(renderer, doc) {
     },
 
     this.$tryReplace = function(range, replacement) {
-        var input = this.doc.getTextRange(range);
+        var input = this.session.getTextRange(range);
         var replacement = this.$search.replace(input, replacement);
         if (replacement !== null) {
-            range.end = this.doc.replace(range, replacement);
+            range.end = this.session.replace(range, replacement);
             return range;
         } else {
             return null;
@@ -1024,13 +1024,13 @@ var Editor =function(renderer, doc) {
 
     this.$find = function(backwards) {
         if (!this.selection.isEmpty()) {
-            this.$search.set({needle: this.doc.getTextRange(this.getSelectionRange())});
+            this.$search.set({needle: this.session.getTextRange(this.getSelectionRange())});
         }
 
         if (typeof backwards != "undefined")
             this.$search.set({backwards: backwards});
 
-        var range = this.$search.find(this.doc);
+        var range = this.$search.find(this.session);
         if (range) {
             this.gotoLine(range.end.row+1, range.end.column);
             this.$updateDesiredColumn();
@@ -1039,11 +1039,11 @@ var Editor =function(renderer, doc) {
     };
 
     this.undo = function() {
-        this.doc.getUndoManager().undo();
+        this.session.getUndoManager().undo();
     };
 
     this.redo = function() {
-        this.doc.getUndoManager().redo();
+        this.session.getUndoManager().redo();
     };
 
 }).call(Editor.prototype);
diff --git a/lib/ace/layer/cursor.js b/lib/ace/layer/cursor.js
index 7c65aa1e..60a6938e 100644
--- a/lib/ace/layer/cursor.js
+++ b/lib/ace/layer/cursor.js
@@ -52,14 +52,14 @@ var Cursor = function(parentEl) {
 
 (function() {
 
-    this.setDocument = function(doc) {
-        this.doc = doc;
+    this.setSession = function(session) {
+        this.session = session;
     };
 
     this.setCursor = function(position, overwrite) {
         this.position = {
             row : position.row,
-            column : this.doc.documentToScreenColumn(position.row, position.column)
+            column : this.session.documentToScreenColumn(position.row, position.column)
         };
         if (overwrite) {
             dom.addCssClass(this.cursor, "ace_overwrite");
diff --git a/lib/ace/layer/marker.js b/lib/ace/layer/marker.js
index 82e860cb..027212b4 100644
--- a/lib/ace/layer/marker.js
+++ b/lib/ace/layer/marker.js
@@ -51,8 +51,8 @@ var Marker = function(parentEl) {
 
 (function() {
 
-    this.setDocument = function(doc) {
-        this.doc = doc;
+    this.setSession = function(session) {
+        this.session = session;
     };
 
     this.addMarker = function(range, clazz, type) {
@@ -105,7 +105,7 @@ var Marker = function(parentEl) {
 
         // selection start
         var row = range.start.row;
-        var lineRange = new Range(row, range.start.column, row, this.doc.getLine(row).length);
+        var lineRange = new Range(row, range.start.column, row, this.session.getLine(row).length);
         this.drawSingleLineMarker(stringBuilder, lineRange, clazz, layerConfig, 1);
 
         // selection end
@@ -116,13 +116,13 @@ var Marker = function(parentEl) {
         for (var row = range.start.row + 1; row < range.end.row; row++) {
             lineRange.start.row = row;
             lineRange.end.row = row;
-            lineRange.end.column = this.doc.getLine(row).length; // account for endofline characters
+            lineRange.end.column = this.session.getLine(row).length; // account for endofline characters
             this.drawSingleLineMarker(stringBuilder, lineRange, clazz, layerConfig, 1);
         }
     };
 
     this.drawMultiLineMarker = function(stringBuilder, range, clazz, layerConfig) {
-        var range = range.toScreenRange(this.doc);
+        var range = range.toScreenRange(this.session);
 
         // from selection start to the end of the line
         var height = layerConfig.lineHeight;
@@ -164,7 +164,7 @@ var Marker = function(parentEl) {
     };
 
     this.drawSingleLineMarker = function(stringBuilder, range, clazz, layerConfig, extraLength) {
-        var range = range.toScreenRange(this.doc);
+        var range = range.toScreenRange(this.session);
 
         var height = layerConfig.lineHeight;
         var width = Math.round((range.end.column + (extraLength || 0) - range.start.column) * layerConfig.characterWidth);
diff --git a/lib/ace/layer/text.js b/lib/ace/layer/text.js
index 356e4ad3..8ef2ebf3 100644
--- a/lib/ace/layer/text.js
+++ b/lib/ace/layer/text.js
@@ -125,8 +125,8 @@ var Text = function(parentEl) {
         return size;
     };
 
-    this.setDocument = function(doc) {
-        this.doc = doc;
+    this.setSession = function(session) {
+        this.session = session;
     };
 
     this.showInvisibles = false;
@@ -139,7 +139,7 @@ var Text = function(parentEl) {
     };
 
     this.$computeTabString = function() {
-        var tabSize = this.doc.getTabSize();
+        var tabSize = this.session.getTabSize();
         if (this.showInvisibles) {
             var halfTab = (tabSize) / 2;
             this.$tabString = "<span class='ace_invisible'>"
@@ -280,7 +280,7 @@ var Text = function(parentEl) {
         };
 
         if (this.showInvisibles) {
-            if (row !== this.doc.getLength() - 1) {
+            if (row !== this.session.getLength() - 1) {
                 stringBuilder.push("<span class='ace_invisible'>" + this.EOL_CHAR + "</span>");
             } else {
                 stringBuilder.push("<span class='ace_invisible'>" + this.EOF_CHAR + "</span>");
diff --git a/lib/ace/test/change_document_test.js b/lib/ace/test/change_document_test.js
index 77375781..4a91eeb1 100644
--- a/lib/ace/test/change_document_test.js
+++ b/lib/ace/test/change_document_test.js
@@ -49,18 +49,18 @@ var EditSession     = require("../edit_session").EditSession,
 var Test = {
     
     setUp : function(next) {
-        this.doc1 = new EditSession(["abc", "def"]);
-        this.doc2 = new EditSession(["ghi", "jkl"]);        
+        this.session1 = new EditSession(["abc", "def"]);
+        this.session2 = new EditSession(["ghi", "jkl"]);        
         this.editor = new Editor(new MockRenderer());
         next();
     },
 
     "test: change document" : function() {
-        this.editor.setDocument(this.doc1);
-        assert.equal(this.editor.getDocument(), this.doc1);
+        this.editor.setSession(this.session1);
+        assert.equal(this.editor.getSession(), this.session1);
 
-        this.editor.setDocument(this.doc2);
-        assert.equal(this.editor.getDocument(), this.doc2);
+        this.editor.setSession(this.session2);
+        assert.equal(this.editor.getSession(), this.session2);
     },
 
     "test: only changes to the new document should have effect" : function() {
@@ -69,24 +69,24 @@ var Test = {
             called = true;
         };
 
-        this.editor.setDocument(this.doc1);
-        this.editor.setDocument(this.doc2);
+        this.editor.setSession(this.session1);
+        this.editor.setSession(this.session2);
 
-        this.doc1.duplicateLines(0, 0);
+        this.session1.duplicateLines(0, 0);
         assert.notOk(called);
 
-        this.doc2.duplicateLines(0, 0);
+        this.session2.duplicateLines(0, 0);
         assert.ok(called);
     },
 
     "test: should use cursor of new document" : function() {
-        this.doc1.getSelection().moveCursorTo(0, 1);
-        this.doc2.getSelection().moveCursorTo(1, 0);
+        this.session1.getSelection().moveCursorTo(0, 1);
+        this.session2.getSelection().moveCursorTo(1, 0);
 
-        this.editor.setDocument(this.doc1);
+        this.editor.setSession(this.session1);
         assert.position(this.editor.getCursorPosition(), 0, 1);
 
-        this.editor.setDocument(this.doc2);
+        this.editor.setSession(this.session2);
         assert.position(this.editor.getCursorPosition(), 1, 0);
     },
 
@@ -95,28 +95,28 @@ var Test = {
             called = true;
         };
 
-        this.editor.setDocument(this.doc1);
-        this.editor.setDocument(this.doc2);
+        this.editor.setSession(this.session1);
+        this.editor.setSession(this.session2);
         assert.position(this.editor.getCursorPosition(), 0, 0);
 
         var called = false;
-        this.doc1.getSelection().moveCursorTo(0, 1);
+        this.session1.getSelection().moveCursorTo(0, 1);
         assert.position(this.editor.getCursorPosition(), 0, 0);
         assert.notOk(called);
 
-        this.doc2.getSelection().moveCursorTo(1, 1);
+        this.session2.getSelection().moveCursorTo(1, 1);
         assert.position(this.editor.getCursorPosition(), 1, 1);
         assert.ok(called);
     },
 
     "test: should use selection of new document" : function() {
-        this.doc1.getSelection().selectTo(0, 1);
-        this.doc2.getSelection().selectTo(1, 0);
+        this.session1.getSelection().selectTo(0, 1);
+        this.session2.getSelection().selectTo(1, 0);
 
-        this.editor.setDocument(this.doc1);
+        this.editor.setSession(this.session1);
         assert.position(this.editor.getSelection().getSelectionLead(), 0, 1);
 
-        this.editor.setDocument(this.doc2);
+        this.editor.setSession(this.session2);
         assert.position(this.editor.getSelection().getSelectionLead(), 1, 0);
     },
 
@@ -125,16 +125,16 @@ var Test = {
             called = true;
         };
 
-        this.editor.setDocument(this.doc1);
-        this.editor.setDocument(this.doc2);
+        this.editor.setSession(this.session1);
+        this.editor.setSession(this.session2);
         assert.position(this.editor.getSelection().getSelectionLead(), 0, 0);
 
         var called = false;
-        this.doc1.getSelection().selectTo(0, 1);
+        this.session1.getSelection().selectTo(0, 1);
         assert.position(this.editor.getSelection().getSelectionLead(), 0, 0);
         assert.notOk(called);
 
-        this.doc2.getSelection().selectTo(1, 1);
+        this.session2.getSelection().selectTo(1, 1);
         assert.position(this.editor.getSelection().getSelectionLead(), 1, 1);
         assert.ok(called);
     },
@@ -143,14 +143,14 @@ var Test = {
         this.editor.onDocumentModeChange = function() {
             called = true;
         };
-        this.editor.setDocument(this.doc1);
-        this.editor.setDocument(this.doc2);
+        this.editor.setSession(this.session1);
+        this.editor.setSession(this.session2);
 
         var called = false;
-        this.doc1.setMode(new Text());
+        this.session1.setMode(new Text());
         assert.notOk(called);
 
-        this.doc2.setMode(new JavaScriptMode());
+        this.session2.setMode(new JavaScriptMode());
         assert.ok(called);
     }
 };
diff --git a/lib/ace/test/mockrenderer.js b/lib/ace/test/mockrenderer.js
index ec068536..be4cd520 100644
--- a/lib/ace/test/mockrenderer.js
+++ b/lib/ace/test/mockrenderer.js
@@ -69,8 +69,12 @@ MockRenderer.prototype.getMouseEventTarget = function() {
     return this.container;
 };
 
-MockRenderer.prototype.setDocument = function(doc) {
-    this.doc = doc;
+MockRenderer.prototype.setSession = function(session) {
+    this.session = session;
+};
+
+MockRenderer.prototype.getSession = function(session) {
+    return this.session;
 };
 
 MockRenderer.prototype.setTokenizer = function() {
@@ -91,7 +95,7 @@ MockRenderer.prototype.scrollCursorIntoView = function() {
 };
 
 MockRenderer.prototype.scrollToRow = function(row) {
-    var row = Math.min(this.doc.getLength() - this.visibleRowCount, Math.max(0,
+    var row = Math.min(this.session.getLength() - this.visibleRowCount, Math.max(0,
                                                                           row));
     this.layerConfig.firstVisibleRow = row;
     this.layerConfig.lastVisibleRow = row + this.visibleRowCount;
diff --git a/lib/ace/test/virtual_renderer_test.js b/lib/ace/test/virtual_renderer_test.js
index 24d6e2f3..83e0351c 100644
--- a/lib/ace/test/virtual_renderer_test.js
+++ b/lib/ace/test/virtual_renderer_test.js
@@ -38,7 +38,7 @@
 define(function(require, exports, module) {
 require("./mockdom");
 
-var Document        = require("../document").Document,
+var EditSession     = require("ace/edit_session").EditSession,
     VirtualRenderer = require("../virtual_renderer").VirtualRenderer,
     assert          = require("./assertions");
 
@@ -54,7 +54,7 @@ var Test = {
         document.body.appendChild(el);
 
         var renderer = new VirtualRenderer(el);
-        renderer.setDocument(new Document("1234"));
+        renderer.setSession(new EditSession("1234"));
 
         renderer.characterWidth = 10;
         renderer.lineHeight = 15;
diff --git a/lib/ace/virtual_renderer.js b/lib/ace/virtual_renderer.js
index 45f61c0f..687085fa 100644
--- a/lib/ace/virtual_renderer.js
+++ b/lib/ace/virtual_renderer.js
@@ -133,11 +133,11 @@ var VirtualRenderer = function(container, theme) {
 
     oop.implement(this, EventEmitter);
 
-    this.setDocument = function(doc) {
-        this.doc = doc;
-        this.$cursorLayer.setDocument(doc);
-        this.$markerLayer.setDocument(doc);
-        this.$textLayer.setDocument(doc);
+    this.setSession = function(session) {
+        this.session = session;
+        this.$cursorLayer.setSession(session);
+        this.$markerLayer.setSession(session);
+        this.$textLayer.setSession(session);
 
         this.$loop.schedule(this.CHANGE_FULL);
     };
@@ -193,7 +193,7 @@ var VirtualRenderer = function(container, theme) {
             this.scroller.style.height = height + "px";
             this.scrollBar.setHeight(height);
 
-            if (this.doc) {
+            if (this.session) {
                 this.scrollToY(this.getScrollTop());
                 changes = changes | this.CHANGE_FULL;
             }
@@ -322,12 +322,12 @@ var VirtualRenderer = function(container, theme) {
     };
 
     this.$updateScrollBar = function() {
-        this.scrollBar.setInnerHeight(this.doc.getLength() * this.lineHeight);
+        this.scrollBar.setInnerHeight(this.session.getLength() * this.lineHeight);
         this.scrollBar.setScrollTop(this.scrollTop);
     };
 
     this.$renderChanges = function(changes) {
-        if (!changes || !this.doc || !this.$tokenizer)
+        if (!changes || !this.session || !this.$tokenizer)
             return;
         
         // text, scrolling and resize changes can cause the view port size to change
@@ -395,7 +395,7 @@ var VirtualRenderer = function(container, theme) {
 
         var lineCount = Math.ceil(minHeight / this.lineHeight);
         var firstRow = Math.max(0, Math.round((this.scrollTop - offset) / this.lineHeight));
-        var lastRow = Math.max(0, Math.min(this.doc.getLength(), firstRow + lineCount) - 1);
+        var lastRow = Math.max(0, Math.min(this.session.getLength(), firstRow + lineCount) - 1);
 
         var layerConfig = this.layerConfig = {
             width : longestLine,
@@ -441,7 +441,7 @@ var VirtualRenderer = function(container, theme) {
     };
 
     this.$getLongestLine = function() {
-        var charCount = this.doc.getScreenWidth();
+        var charCount = this.session.getScreenWidth();
         if (this.$textLayer.showInvisibles)
             charCount += 1;
 
@@ -530,7 +530,7 @@ var VirtualRenderer = function(container, theme) {
     };
 
     this.scrollToY = function(scrollTop) {
-        var maxHeight = this.doc.getLength() * this.lineHeight - this.$size.scrollerHeight;
+        var maxHeight = this.session.getLength() * this.lineHeight - this.$size.scrollerHeight;
         var scrollTop = Math.max(0, Math.min(maxHeight, scrollTop));
 
         if (this.scrollTop !== scrollTop) {
@@ -561,14 +561,14 @@ var VirtualRenderer = function(container, theme) {
 
         return {
             row : row,
-            column : this.doc.screenToDocumentColumn(Math.max(0, Math.min(row, this.doc.getLength()-1)), col)
+            column : this.session.screenToDocumentColumn(Math.max(0, Math.min(row, this.session.getLength()-1)), col)
         };
     };
 
     this.textToScreenCoordinates = function(row, column) {
         var canvasPos = this.scroller.getBoundingClientRect();
 
-        var x = this.$padding + Math.round(this.doc.documentToScreenColumn(row, column) * this.characterWidth);
+        var x = this.$padding + Math.round(this.session.documentToScreenColumn(row, column) * this.characterWidth);
         var y = row * this.lineHeight;
 
         return {