diff --git a/gridstack.js b/gridstack.js
new file mode 100644
index 0000000..7ba5f00
--- /dev/null
+++ b/gridstack.js
@@ -0,0 +1,298 @@
+(function (scope, _) {
+
+    var Utils = {
+        is_intercepted: function (a, b) {
+            return !(a.x + a.width <= b.x || b.x + b.width <= a.x || a.y + a.height <= b.y || b.y + b.height <= a.y);
+        }
+    };
+
+    var id_seq = 0;
+
+    var GridStackEngine = function (width, onchange) {
+        this.width = width;
+
+        this.nodes = [];
+        this.onchange = onchange || function () {};
+    };
+
+    GridStackEngine.prototype._fix_collisions = function (node) {
+        this.nodes = _.sortBy(this.nodes, function (n) { return -(n.x + n.y * this.width); }, this);
+
+        while (true) {
+            var collision_node = _.find(this.nodes, function (n) {
+                return n != node && Utils.is_intercepted(n, node);
+            }, this);
+            if (typeof collision_node == 'undefined') {
+                return;
+            }
+            this.move_node(collision_node, collision_node.x, node.y + node.height,
+                collision_node.width, collision_node.height, true);
+        }
+    };
+
+    GridStackEngine.prototype._pack_nodes = function () {
+        this.nodes = _.sortBy(this.nodes, function (n) { return n.x + n.y * this.width; }, this);
+
+        _.each(this.nodes, function (n, i) {
+            while (n.y > 0) {
+                var new_y = n.y - 1;
+                var can_be_moved = i == 0;
+
+                if (i > 0) {
+                    var collision_node = _.chain(this.nodes)
+                        .first(i)
+                        .find(function (bn) {
+                            return Utils.is_intercepted({x: n.x, y: new_y, width: n.width, height: n.height}, bn);
+                        })
+                        .value();
+                    can_be_moved = typeof collision_node == 'undefined';
+                }
+
+                if (!can_be_moved) {
+                    break;
+                }
+                n.y = new_y;
+            }
+        }, this);
+    };
+
+    GridStackEngine.prototype._prepare_node = function (node, moving) {
+        node = _.defaults(node || {}, {width: 1, height: 1, x: 0, y: 0 });
+
+        node.x = parseInt('' + node.x);
+        node.y = parseInt('' + node.y);
+        node.width = parseInt('' + node.width);
+        node.height = parseInt('' + node.height);
+
+        if (node.width > this.width) {
+            node.width = this.width;
+        }
+        else if (node.width < 1) {
+            node.width = 1;
+        }
+
+        if (node.height < 1) {
+            node.height = 1;
+        }
+
+        if (node.x < 0) {
+            node.x = 0;
+        }
+
+        if (node.x + node.width > this.width) {
+            if (moving) {
+                node.x = this.width - node.width;
+            }
+            else {
+                node.width = this.width - node.x;
+            }
+        }
+
+        if (node.y < 0) {
+            node.y = 0;
+        }
+
+        return node;
+    };
+
+    GridStackEngine.prototype._notify = function () {
+        this.onchange(this.nodes);
+    };
+
+    GridStackEngine.prototype.add_node = function(node) {
+        node = this._prepare_node(node);
+
+        if (typeof node.max_width != 'undefined') node.width = Math.min(node.width, node.max_width);
+        if (typeof node.max_height != 'undefined') node.height = Math.min(node.height, node.max_height);
+        if (typeof node.min_width != 'undefined') node.width = Math.max(node.width, node.min_width);
+        if (typeof node.min_height != 'undefined') node.height = Math.max(node.height, node.min_height);
+
+        node._id = ++id_seq;
+        this.nodes.push(node);
+        this._fix_collisions(node);
+        this._pack_nodes();
+        this._notify();
+        return node;
+    };
+
+    GridStackEngine.prototype.remove_node = function (node) {
+        node._id = null;
+        this.nodes = _.without(this.nodes, node);
+        this._pack_nodes();
+        this._notify(node);
+    };
+
+    GridStackEngine.prototype.move_node = function (node, x, y, width, height, no_pack) {
+        if (typeof x == 'undefined') x = node.x;
+        if (typeof y == 'undefined') y = node.y;
+        if (typeof width == 'undefined') width = node.width;
+        if (typeof height == 'undefined') height = node.height;
+
+        if (typeof node.max_width != 'undefined') width = Math.min(width, node.max_width);
+        if (typeof node.max_height != 'undefined') height = Math.min(height, node.max_height);
+        if (typeof node.min_width != 'undefined') width = Math.max(width, node.min_width);
+        if (typeof node.min_height != 'undefined') height = Math.max(height, node.min_height);
+
+        if (node.x == x && node.y == y && node.width == width && node.height == height) {
+            return node;
+        }
+
+        var moving = node.x != x;
+
+        node.x = x;
+        node.y = y;
+        node.width = width;
+        node.height = height;
+
+        node = this._prepare_node(node, moving);
+
+        this._fix_collisions(node);
+        if (!no_pack) {
+            this._pack_nodes();
+            this._notify();
+        }
+        return node;
+    };
+
+    GridStackEngine.prototype.get_grid_height = function () {
+        return _.reduce(this.nodes, function (memo, n) { return Math.max(memo, n.y + n.height); }, 0);
+    };
+
+    var GridStack = function (el, opts) {
+        var self = this;
+
+        this.container = $(el);
+
+        this.opts = _.defaults(opts || {}, {
+            width: 12,
+            item_class: 'grid-stack-item',
+            placeholder_class: 'grid-stack-placeholder',
+            handle: '.grid-stack-item-content',
+            cell_height: 60,
+            vertical_margin: 20
+        });
+
+        this.grid = new GridStackEngine(this.opts.width, function (nodes) {
+            _.each(nodes, function (n) {
+                n.el
+                    .attr('data-gs-x', n.x)
+                    .attr('data-gs-y', n.y)
+                    .attr('data-gs-width', n.width)
+                    .attr('data-gs-height', n.height);
+            });
+        });
+
+        this.container.find('.' + this.opts.item_class).each(function (index, el) {
+            self._prepare_element(el);
+        });
+
+        this.placeholder = $('<div class="' + this.opts.placeholder_class + ' ' + this.opts.item_class + '"><div class="placeholder-content" /></div>').hide();
+        this.container.append(this.placeholder);
+        this.container.height((this.grid.get_grid_height()) * (this.opts.cell_height + this.opts.vertical_margin) - this.opts.vertical_margin);
+    };
+
+    GridStack.prototype._update_container_height = function () {
+        this.container.height(this.grid.get_grid_height() * (this.opts.cell_height + this.opts.vertical_margin) - this.opts.vertical_margin);
+    };
+
+    GridStack.prototype._prepare_element = function (el) {
+        var self = this;
+        el = $(el);
+
+        var node = self.grid.add_node({
+            x: el.attr('data-gs-x'),
+            y: el.attr('data-gs-y'),
+            width: el.attr('data-gs-width'),
+            height: el.attr('data-gs-height'),
+            max_width: el.attr('data-gs-max-width'),
+            min_width: el.attr('data-gs-min-width'),
+            max_height: el.attr('data-gs-max-height'),
+            min_height: el.attr('data-gs-min-height'),
+            el: el
+        });
+        el.data('_gridstack_node', node);
+
+        var cell_width, cell_height = this.opts.cell_height + this.opts.vertical_margin / 2;
+
+        var on_start_moving = function (event, ui) {
+            var o = $(this);
+            cell_width = Math.ceil(o.outerWidth() / o.attr('data-gs-width'));
+            self.placeholder
+                .attr('data-gs-x', o.attr('data-gs-x'))
+                .attr('data-gs-y', o.attr('data-gs-y'))
+                .attr('data-gs-width', o.attr('data-gs-width'))
+                .attr('data-gs-height', o.attr('data-gs-height'))
+                .show();
+            node.el = self.placeholder;
+        };
+
+        var on_end_moving = function (event, ui) {
+            var o = $(this);
+            node.el = o;
+            self.placeholder.hide();
+            o
+                .attr('data-gs-x', node.x)
+                .attr('data-gs-y', node.y)
+                .attr('data-gs-width', node.width)
+                .attr('data-gs-height', node.height)
+                .removeAttr('style');
+            self._update_container_height();
+        };
+
+        el.draggable({
+            handle: this.opts.handle,
+            scroll: true,
+            appendTo: 'body',
+
+            start: on_start_moving,
+            stop: on_end_moving,
+            drag: function (event, ui) {
+                var x = Math.round(ui.position.left / cell_width),
+                    y = Math.floor(ui.position.top / cell_height);
+                self.grid.move_node(node, x, y);
+                self._update_container_height();
+            }
+        }).resizable({
+            autoHide: true,
+            handles: 'se',
+            minHeight: this.opts.cell_height - 10,
+            minWidth: 70,
+
+            start: on_start_moving,
+            stop: on_end_moving,
+            resize: function (event, ui) {
+                var width = Math.round(ui.size.width / cell_width),
+                    height = Math.round(ui.size.height / cell_height);
+                self.grid.move_node(node, node.x, node.y, width, height);
+                self._update_container_height();
+            }
+        });
+    };
+
+    GridStack.prototype.add_widget = function (el, x, y, width, height) {
+        el = $(el);
+        if (typeof x != 'undefined') el.attr('data-gs-x', x);
+        if (typeof y != 'undefined') el.attr('data-gs-y', y);
+        if (typeof width != 'undefined') el.attr('data-gs-width', width);
+        if (typeof height != 'undefined') el.attr('data-gs-height', height);
+        this.container.append(el);
+        this._prepare_element(el);
+    };
+
+    GridStack.prototype.remove_widget = function (el) {
+        var node = $(el).data('_gridstack_node');
+        this.grid.remove_node(node);
+        el.remove();
+    };
+
+    scope.GridStackUI = GridStack;
+
+    $.fn.gridstack = function (opts) {
+        return this.each(function () {
+            if (!$(this).data('_gridstack')) {
+                $(this).data('_gridstack', new GridStack(this, opts));
+            }
+        });
+    };
+
+})(window, _);