diff --git a/package.json b/package.json
index 80d5086d4..ae29becb1 100644
--- a/package.json
+++ b/package.json
@@ -53,6 +53,7 @@
     "http-errors": "^1.4.0",
     "imports-loader": "^0.6.5",
     "isomorphic-fetch": "^2.2.1",
+    "js-tree": "^1.1.0",
     "json-loader": "^0.5.4",
     "jsonwebtoken": "^5.7.0",
     "koa": "^2.0.0",
diff --git a/src/components/Tree/Node.js b/src/components/Tree/Node.js
new file mode 100644
index 000000000..ab58dcc44
--- /dev/null
+++ b/src/components/Tree/Node.js
@@ -0,0 +1,108 @@
+var React = require('react');
+
+import styles from './Tree.scss';
+import classNames from 'classnames/bind';
+const cx = classNames.bind(styles);
+
+var Node = React.createClass({
+  displayName: 'UITreeNode',
+
+  renderCollapse() {
+    var index = this.props.index;
+
+    if(index.children && index.children.length) {
+      var collapsed = index.node.collapsed;
+
+      return (
+        <span
+          className={cx(styles.collapse, collapsed ? styles.caretRight : styles.caretDown)}
+          onMouseDown={function(e) {e.stopPropagation()}}
+          onClick={this.handleCollapse}
+        >
+          <img src={ require("./assets/chevron.svg") } />
+        </span>
+      );
+    }
+
+    return null;
+  },
+
+  renderChildren() {
+    var index = this.props.index;
+    var tree = this.props.tree;
+    var dragging = this.props.dragging;
+
+    if(index.children && index.children.length) {
+      var childrenStyles = {};
+
+      if (!this.props.rootNode) {
+        if(index.node.collapsed) childrenStyles.display = 'none';
+        childrenStyles['paddingLeft'] = this.props.paddingLeft + 'px';
+      }
+
+      return (
+        <div className={ styles.children } style={childrenStyles}>
+          {index.children.map((child) => {
+            var childIndex = tree.getIndex(child);
+            return (
+              <Node
+                tree={tree}
+                index={childIndex}
+                key={childIndex.id}
+                dragging={dragging}
+                paddingLeft={this.props.paddingLeft}
+                onCollapse={this.props.onCollapse}
+                onDragStart={this.props.onDragStart}
+              />
+            );
+          })}
+        </div>
+      );
+    }
+
+    return null;
+  },
+
+  render() {
+    var tree = this.props.tree;
+    var index = this.props.index;
+    var dragging = this.props.dragging;
+    var node = index.node;
+    var style = {};
+
+    return (
+      <div className={cx(styles.node, {
+        placeholder: index.id === dragging,
+        rootNode: this.props.rootNode,
+      })} style={style}>
+        <div className={ styles.inner } ref="inner" onMouseDown={this.handleMouseDown}>
+          {!this.props.rootNode && this.renderCollapse()}
+          <span
+            className={ cx(styles.nodeLabel, { rootLabel: this.props.rootNode }) }
+            onClick={() => {}}
+          >
+            {node.module.name}
+          </span>
+        </div>
+        {this.renderChildren()}
+      </div>
+    );
+  },
+
+  handleCollapse(e) {
+    e.stopPropagation();
+    var nodeId = this.props.index.id;
+    if(this.props.onCollapse) this.props.onCollapse(nodeId);
+  },
+
+  handleMouseDown(e) {
+    var nodeId = this.props.index.id;
+    var dom = this.refs.inner;
+
+    if(this.props.onDragStart) {
+      this.props.onDragStart(nodeId, dom, e);
+    }
+  }
+});
+
+module.exports = Node;
\ No newline at end of file
diff --git a/src/components/Tree/Tree.js b/src/components/Tree/Tree.js
new file mode 100644
index 000000000..f5d4b8e3f
--- /dev/null
+++ b/src/components/Tree/Tree.js
@@ -0,0 +1,68 @@
+var Tree = require('js-tree');
+var proto = Tree.prototype;
+
+proto.updateNodesPosition = function() {
+  var top = 1;
+  var left = 1;
+  var root = this.getIndex(1);
+  var self = this;
+
+  root.top = top++;
+  root.left = left++;
+
+  if(root.children && root.children.length) {
+    walk(root.children, root, left, root.node.collapsed);
+  }
+
+  function walk(children, parent, left, collapsed) {
+    var height = 1;
+    children.forEach(function(id) {
+      var node = self.getIndex(id);
+      if(collapsed) {
+        node.top = null;
+        node.left = null;
+      } else {
+        node.top = top++;
+        node.left = left;
+      }
+
+      if(node.children && node.children.length) {
+        height += walk(node.children, node, left+1, collapsed || node.node.collapsed);
+      } else {
+        node.height = 1;
+        height += 1;
+      }
+    });
+
+    if(parent.node.collapsed) parent.height = 1;
+    else parent.height = height;
+    return parent.height;
+  }
+};
+
+proto.move = function(fromId, toId, placement) {
+  if(fromId === toId || toId === 1) return;
+
+  var obj = this.remove(fromId);
+  var index = null;
+
+  if(placement === 'before') index = this.insertBefore(obj, toId);
+  else if(placement === 'after') index = this.insertAfter(obj, toId);
+  else if(placement === 'prepend') index = this.prepend(obj, toId);
+  else if(placement === 'append') index = this.append(obj, toId);
+
+  // todo: perf
+  this.updateNodesPosition();
+  return index;
+};
+
+proto.getNodeByTop = function(top) {
+  var indexes = this.indexes;
+  for(var id in indexes) {
+    if(indexes.hasOwnProperty(id)) {
+      if(indexes[id].top === top) return indexes[id];
+    }
+  }
+};
+
+module.exports = Tree;
\ No newline at end of file
diff --git a/src/components/Tree/Tree.scss b/src/components/Tree/Tree.scss
new file mode 100644
index 000000000..219c4e8e7
--- /dev/null
+++ b/src/components/Tree/Tree.scss
@@ -0,0 +1,79 @@
+@mixin no-select {
+  -webkit-user-select: none;
+  -khtml-user-select: none;
+  -moz-user-select: none;
+  -ms-user-select: none;
+  user-select: none;
+}
+
+.tree {
+  position: relative;
+  overflow: hidden;
+  @include no-select;
+}
+
+.draggable {
+  position: absolute;
+  opacity: 0.8;
+  @include no-select;
+}
+
+.node {
+  &.placeholder > * {
+    visibility: hidden;
+  }
+
+  &.placeholder {
+    border: 1px dashed #ccc;
+  }
+
+  .inner {
+    position: relative;
+    cursor: pointer;
+    padding-left: 10px;
+  }
+
+  .collapse {
+    position: absolute;
+    left: 0;
+    cursor: pointer;
+
+    width: 20px;
+    height: 25px;
+  }
+
+  .caretRight {
+    margin-top: 3px;
+    margin-left: -3px;
+  }
+
+  .caretDown {
+    transform: rotate(90deg);
+    margin-left: -4px;
+    margin-top: 2px;
+  }
+}
+
+.node {
+  &.placeholder {
+    border: 1px dashed #1385e5;
+  }
+
+  .inner {
+    font-size: 14px;
+  }
+
+  .nodeLabel {
+    display: inline-block;
+    width: 100%;
+    padding: 4px 5px;
+
+    &.isActive {
+      background-color: #31363F;
+    }
+  }
+
+  .rootLabel {
+    color: #ccc;
+  }
+}
\ No newline at end of file
diff --git a/src/components/Tree/UiTree.js b/src/components/Tree/UiTree.js
new file mode 100644
index 000000000..640be2c79
--- /dev/null
+++ b/src/components/Tree/UiTree.js
@@ -0,0 +1,266 @@
+var React = require('react');
+var Tree = require('./tree');
+var Node = require('./node');
+
+import styles from './Tree.scss';
+
+module.exports = React.createClass({
+  displayName: 'UITree',
+
+  propTypes: {
+    tree: React.PropTypes.object.isRequired,
+    paddingLeft: React.PropTypes.number,
+    renderNode: React.PropTypes.func.isRequired
+  },
+
+  getDefaultProps() {
+    return {
+      paddingLeft: 20
+    };
+  },
+
+  getInitialState() {
+    return this.init(this.props);
+  },
+
+  componentWillReceiveProps(nextProps) {
+    if(!this._updated) this.setState(this.init(nextProps));
+    else this._updated = false;
+  },
+
+  init(props) {
+    var tree = new Tree(props.tree);
+    tree.isNodeCollapsed = props.isNodeCollapsed;
+    tree.renderNode = props.renderNode;
+    tree.changeNodeCollapsed = props.changeNodeCollapsed;
+    tree.updateNodesPosition();
+
+    return {
+      tree: tree,
+      dragging: {
+        id: null,
+        x: null,
+        y: null,
+        w: null,
+        h: null
+      }
+    };
+  },
+
+  getDraggingDom() {
+    var tree = this.state.tree;
+    var dragging = this.state.dragging;
+
+    if(dragging && dragging.id) {
+      var draggingIndex = tree.getIndex(dragging.id);
+      var draggingStyles = {
+        top: dragging.y,
+        left: dragging.x,
+        width: dragging.w
+      };
+
+      return (
+        <div className={ styles.draggable } style={draggingStyles}>
+          <Node
+            tree={tree}
+            index={draggingIndex}
+            paddingLeft={this.props.paddingLeft}
+          />
+        </div>
+      );
+    }
+
+    return null;
+  },
+
+  render() {
+    var tree = this.state.tree;
+    var dragging = this.state.dragging;
+    var draggingDom = this.getDraggingDom();
+
+    return (
+      <div className={ styles.tree }>
+        {draggingDom}
+        <Node
+          rootNode={ true }
+          tree={tree}
+          index={tree.getIndex(1)}
+          key={1}
+          paddingLeft={this.props.paddingLeft}
+          onDragStart={this.dragStart}
+          onCollapse={this.toggleCollapse}
+          dragging={dragging && dragging.id}
+        />
+      </div>
+    );
+  },
+
+  dragStart(id, dom, e) {
+    this.dragging = {
+      id: id,
+      w: dom.offsetWidth,
+      h: dom.offsetHeight,
+      x: dom.offsetLeft,
+      y: dom.offsetTop
+    };
+
+    this._startX = dom.offsetLeft;
+    this._startY = dom.offsetTop;
+    this._offsetX = e.clientX;
+    this._offsetY = e.clientY;
+    this._start = true;
+
+    window.addEventListener('mousemove', this.drag);
+    window.addEventListener('mouseup', this.dragEnd);
+  },
+
+  // oh
+  drag(e) {
+    if(this._start) {
+      this.setState({
+        dragging: this.dragging
+      });
+      this._start = false;
+    }
+
+    var tree = this.state.tree;
+    var dragging = this.state.dragging;
+    var paddingLeft = this.props.paddingLeft;
+    var newIndex = null;
+    var index = tree.getIndex(dragging.id);
+    var collapsed = index.node.collapsed;
+
+    var _startX = this._startX;
+    var _startY = this._startY;
+    var _offsetX = this._offsetX;
+    var _offsetY = this._offsetY;
+
+    var pos = {
+      x: _startX + e.clientX - _offsetX,
+      y: _startY + e.clientY - _offsetY
+    };
+    dragging.x = pos.x;
+    dragging.y = pos.y;
+
+    var diffX = dragging.x - paddingLeft/2 - (index.left-2) * paddingLeft;
+    var diffY = dragging.y - dragging.h/2 - (index.top-2) * dragging.h;
+
+    if(diffX < 0) { // left
+      if(index.parent && !index.next) {
+        newIndex = tree.move(index.id, index.parent, 'after');
+      }
+    } else if(diffX > paddingLeft) { // right
+      if(index.prev) {
+        var prevNode = tree.getIndex(index.prev).node;
+        if(!prevNode.collapsed && !prevNode.leaf) {
+          newIndex = tree.move(index.id, index.prev, 'append');
+        }
+      }
+    }
+
+    if(newIndex) {
+      index = newIndex;
+      newIndex.node.collapsed = collapsed;
+      dragging.id = newIndex.id;
+    }
+
+    if(diffY < 0) { // up
+      var above = tree.getNodeByTop(index.top-1);
+      newIndex = tree.move(index.id, above.id, 'before');
+    } else if(diffY > dragging.h) { // down
+      if(index.next) {
+        var below = tree.getIndex(index.next);
+        if(below.children && below.children.length && !below.node.collapsed) {
+          newIndex = tree.move(index.id, index.next, 'prepend');
+        } else {
+          newIndex = tree.move(index.id, index.next, 'after');
+        }
+      } else {
+        var below = tree.getNodeByTop(index.top+index.height);
+        if(below && below.parent !== index.id) {
+          if(below.children && below.children.length) {
+            newIndex = tree.move(index.id, below.id, 'prepend');
+          } else {
+            newIndex = tree.move(index.id, below.id, 'after');
+          }
+        }
+      }
+    }
+
+    if(newIndex) {
+      newIndex.node.collapsed = collapsed;
+      dragging.id = newIndex.id;
+    }
+
+    this.setState({
+      tree: tree,
+      dragging: dragging
+    });
+  },
+
+  dragEnd() {
+    this.setState({
+      dragging: {
+        id: null,
+        x: null,
+        y: null,
+        w: null,
+        h: null
+      }
+    });
+
+    this.change(this.state.tree);
+    window.removeEventListener('mousemove', this.drag);
+    window.removeEventListener('mouseup', this.dragEnd);
+  },
+
+  change(tree) {
+    this._updated = true;
+    if(this.props.onChange) this.props.onChange(tree.obj);
+  },
+
+  toggleCollapse(nodeId) {
+    var tree = this.state.tree;
+    var index = tree.getIndex(nodeId);
+    var node = index.node;
+    node.collapsed = !node.collapsed;
+    tree.updateNodesPosition();
+
+    this.setState({
+      tree: tree
+    });
+
+    this.change(tree);
+  },
+
+  // buildTreeNumbering(tree) {
+  //   const numberBuilder = (index, node, parentNumbering) => {
+  //     let numbering = parentNumbering ? `${parentNumbering}.${index}` : index;
+  //     let children;
+  //     if (node.children) {
+  //       children = node.children.map((child, childIndex) => {
+  //         return numberBuilder(childIndex+1, child, numbering);
+  //       });
+  //     }
+
+  //     const data = {
+  //       module: {
+  //         ...node.module,
+  //         index: numbering,
+  //       }
+  //     }
+  //     if (children) {
+  //       data.children = children;
+  //     }
+
+  //     return data;
+  //   };
+
+  //   const newTree = {...tree};
+  //   newTree.children = [];
+  //   tree.children.forEach((child, index) => {
+  //     newTree.children.push(numberBuilder(index+1, child));
+  //   })
+  //   return newTree;
+  // }
+});
diff --git a/src/components/Tree/assets/chevron.svg b/src/components/Tree/assets/chevron.svg
new file mode 100644
index 000000000..4daab5920
--- /dev/null
+++ b/src/components/Tree/assets/chevron.svg
@@ -0,0 +1 @@
+<svg xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" version="1.1" viewBox="0 0 24 30" x="0px" y="0px"><path d="M8.59,18.16L14.25,12.5L8.59,6.84L7.89,7.55L12.84,12.5L7.89,17.45L8.59,18.16Z"/></svg>
\ No newline at end of file
diff --git a/src/components/Tree/index.js b/src/components/Tree/index.js
new file mode 100644
index 000000000..282ed6e1b
--- /dev/null
+++ b/src/components/Tree/index.js
@@ -0,0 +1,2 @@
+import UiTree from './UiTree';
+export default UiTree;
\ No newline at end of file
diff --git a/src/scenes/DocumentScene/DocumentScene.js b/src/scenes/DocumentScene/DocumentScene.js
index b9bf84956..e0f0f5b47 100644
--- a/src/scenes/DocumentScene/DocumentScene.js
+++ b/src/scenes/DocumentScene/DocumentScene.js
@@ -9,13 +9,48 @@ import AtlasPreviewLoading from 'components/AtlasPreviewLoading';
 import CenteredContent from 'components/CenteredContent';
 import Document from 'components/Document';
 import DropdownMenu, { MenuItem } from 'components/DropdownMenu';
+import Flex from 'components/Flex';
+import Tree from 'components/Tree';
 
 import styles from './DocumentScene.scss';
+import classNames from 'classnames/bind';
+const cx = classNames.bind(styles);
+
+import treeStyles from 'components/Tree/Tree.scss';
+
+const tree = {
+  module: {
+    name: "Introduction",
+    id: "1",
+  },
+  children: [{
+    collapsed: false,
+    module: {
+      name: "dist",
+      id: "2"
+    },
+    children: [
+      {
+        module: {
+          name: "Details",
+          id: "21",
+        },
+      },
+      {
+        module: {
+          name: "Distribution",
+          id: "22",
+        },
+      }
+    ]
+  }]
+};
 
 @observer
 class DocumentScene extends React.Component {
   state = {
     didScroll: false,
+    tree: tree,
   }
 
   componentDidMount = () => {
@@ -43,6 +78,26 @@ class DocumentScene extends React.Component {
     };
   }
 
+  renderNode = (node) => {
+    return (
+      <span className={ treeStyles.nodeLabel } onClick={this.onClickNode.bind(null, node)}>
+        {node.module.name}
+      </span>
+    );
+  }
+
+  onClickNode = (node) => {
+    this.setState({
+      active: node
+    });
+  }
+
+  handleChange = (tree) => {
+    this.setState({
+      tree: tree
+    });
+  }
+
   render() {
     const doc = store.document;
     let title;
@@ -74,13 +129,28 @@ class DocumentScene extends React.Component {
         titleText={ titleText }
         actions={ actions }
       >
-        <CenteredContent>
-          { store.isFetching ? (
+        { store.isFetching ? (
+          <CenteredContent>
             <AtlasPreviewLoading />
-          ) : (
-            <Document document={ doc } />
-          ) }
-        </CenteredContent>
+          </CenteredContent>
+        ) : (
+          <Flex flex={ true }>
+            <div className={ styles.sidebar }>
+              <Tree
+                paddingLeft={20}
+                tree={this.state.tree}
+                onChange={this.handleChange}
+                isNodeCollapsed={this.isNodeCollapsed}
+                renderNode={this.renderNode}
+              />
+            </div>
+            <Flex flex={ true } justify={ 'center' }>
+              <CenteredContent>
+                <Document document={ doc } />
+              </CenteredContent>
+            </Flex>
+          </Flex>
+        ) }
       </Layout>
     );
   }
diff --git a/src/scenes/DocumentScene/DocumentScene.scss b/src/scenes/DocumentScene/DocumentScene.scss
index c7d614611..2a9b34235 100644
--- a/src/scenes/DocumentScene/DocumentScene.scss
+++ b/src/scenes/DocumentScene/DocumentScene.scss
@@ -1,4 +1,9 @@
 .actions {
   display: flex;
   flex-direction: row;
-}
\ No newline at end of file
+}
+
+.sidebar {
+  width: 250px;
+  padding: 40px 20px;
+}