diff --git a/src/mainwindow.h b/src/mainwindow.h
--- a/src/mainwindow.h
+++ b/src/mainwindow.h
@@ -17,16 +17,35 @@
 */
 #pragma once
 
-#include <QMainWindow>
-#include <QUrl>
 #include <KTextEditor/View>
 #include <KXmlGui/KXmlGuiWindow>
+#include <QMainWindow>
+#include <QMap>
+#include <QPair>
+#include <QPushButton>
+#include <QStackedWidget>
+#include <QToolButton>
+#include <QUrl>
 
 namespace Ui
 {
 class MainWindow;
 }
 
+struct LateralArea {
+    // Area with the the lateral buttons that will open the views.
+    // Kind like the KDevelop stuff but way simpler.
+    using Btn2Widget = QPair<QPushButton*, QWidget*>;
+    using WidgetMap = QMap<QString, Btn2Widget>;
+
+    QWidget *m_toolBar;
+    QStackedWidget *m_stack;
+    WidgetMap m_map;
+    template<typename T> T* get(const QString& s) {
+        return qobject_cast<T*>(m_map[s].second);
+    }
+};
+
 class MainWindow : public KXmlGuiWindow
 {
     Q_OBJECT
@@ -38,7 +57,11 @@
 private:
     Ui::MainWindow *ui;
     QList<QUrl> m_openFiles;
-    KTextEditor::View *m_curr_editor_view;
+    KTextEditor::View *m_currEditorView;
+    LateralArea m_lateral;
+    QTabWidget *m_instances;
+
+    void setupLateralArea();
     void initWidgets();
     void setupActions();
     void openFile();
diff --git a/src/mainwindow.cpp b/src/mainwindow.cpp
--- a/src/mainwindow.cpp
+++ b/src/mainwindow.cpp
@@ -16,21 +16,31 @@
     You should have received a copy of the GNU General Public License
     along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
+
 #include "mainwindow.h"
 #include "ui_mainwindow.h"
-#include <QFileDialog>
+#include <dialogs/connectsettingsdialog.h>
+#include <dialogs/profilesdialog.h>
 #include <KLocalizedString>
 #include <KStandardAction>
 #include <KActionCollection>
 #include <KXMLGUIFactory>
-#include <dialogs/connectsettingsdialog.h>
-#include <dialogs/profilesdialog.h>
-#include <widgets/gcodeeditorwidget.h>
 #include <memory>
+#include <QFileDialog>
+#include <QToolButton>
+#include <QSplitter>
+#include <QHBoxLayout>
+#include <set>
+#include <widgets/atcoreinstancewidget.h>
+#include <widgets/gcodeeditorwidget.h>
+#include <widgets/videomonitorwidget.h>
+#include <widgets/3dview/viewer3d.h>
+
 MainWindow::MainWindow(QWidget *parent) :
     KXmlGuiWindow(parent),
     ui(new Ui::MainWindow),
-    m_curr_editor_view(nullptr)
+    m_currEditorView(nullptr),
+    m_instances(new QTabWidget(this))
 {
     ui->setupUi(this);
     initWidgets();
@@ -44,11 +54,60 @@
 
 void MainWindow::initWidgets()
 {
-    connect(ui->gcodeEditorWidget, &GCodeEditorWidget::updateClientFactory, this, [ & ](KTextEditor::View* view){
-        guiFactory()->removeClient(m_curr_editor_view);
-        guiFactory()->addClient(view);
-        m_curr_editor_view = view;
-    });
+    auto newInstanceWidget = new AtCoreInstanceWidget();
+    m_instances->addTab(newInstanceWidget, i18n("Connect your printer"));
+
+    setupLateralArea();
+
+    // View:
+    // Sidebar, Sidevar Controls, Printer Tabs.
+    // Sidevar Controls and Printer Tabs can be resized, Sidebar cant.
+    auto *centralLayout = new QHBoxLayout();
+    auto splitter = new QSplitter();
+    splitter->addWidget(m_lateral.m_stack);
+    splitter->addWidget(m_instances);
+    centralLayout->addWidget(m_lateral.m_toolBar);
+    centralLayout->addWidget(splitter);
+    ui->centralwidget->setLayout(centralLayout);
+}
+
+// Move to LateralArea.
+void MainWindow::setupLateralArea()
+{
+    m_lateral.m_toolBar = new QWidget();
+    m_lateral.m_stack = new QStackedWidget();
+    auto *buttonLayout = new QVBoxLayout();
+
+    auto setupButton = [this, buttonLayout](const QString& key, const QString& text, const QIcon& icon, QWidget *w) {
+        auto *btn = new QPushButton(m_lateral.m_toolBar);
+        btn->setToolTip(text);
+        btn->setAutoExclusive(true);
+        btn->setCheckable(true);
+        btn->setIcon(icon);
+        btn->setIconSize(QSize(64,64));
+        btn->setFlat(true);
+        m_lateral.m_stack->addWidget(w);
+        m_lateral.m_map[key] = {btn, w};
+
+        buttonLayout->addWidget(btn);
+        connect(btn, &QToolButton::toggled, [this, w](bool checked) {
+            if (checked)
+                m_lateral.m_stack->setCurrentWidget(w);
+        });
+    };
+
+    auto *gcodeEditor = new GCodeEditorWidget(this);
+     connect(gcodeEditor, &GCodeEditorWidget::updateClientFactory, this, [&](KTextEditor::View* view){
+         guiFactory()->removeClient(m_currEditorView);
+         guiFactory()->addClient(view);
+         m_currEditorView = view;
+     });
+
+    setupButton("3d",    i18n("&3D"), QIcon(":/icon/atelier"), new Viewer3D(this));
+    setupButton("gcode", i18n("&GCode"), QIcon(":/icon/atelier"), gcodeEditor);
+    setupButton("video", i18n("&Video"), QIcon(":/icon/atelier"), new VideoMonitorWidget(this));
+    buttonLayout->addStretch();
+    m_lateral.m_toolBar->setLayout(buttonLayout);
 }
 
 void MainWindow::setupActions()
@@ -90,26 +149,35 @@
 
 void MainWindow::openFile()
 {
-    QUrl fileNameFromDialog = QFileDialog::getOpenFileUrl(this, i18n("Open GCode"),
+    QUrl fileName = QFileDialog::getOpenFileUrl(this, i18n("Open GCode"),
                               QDir::homePath(), i18n("GCode (*.gco *.gcode)"));
-    if (!fileNameFromDialog.isEmpty()) {
-        ui->gcodeEditorWidget->loadFile(fileNameFromDialog);
-        ui->view3DWidget->drawModel(fileNameFromDialog.toString());
-        m_openFiles.append(fileNameFromDialog);
+
+    if (!fileName.isEmpty()) {
+
+        m_lateral.get<GCodeEditorWidget>("gcode")->loadFile(fileName);
+        m_lateral.get<Viewer3D>("3d")->drawModel(fileName.toString());
+
+        const int tabs = m_instances->count();
+        m_openFiles.append(fileName);
+
+        for(int i=0; i < tabs; ++i){
+            auto instance = qobject_cast<AtCoreInstanceWidget*>(m_instances->widget(i));
+            instance->setOpenFiles(m_openFiles);
+        }
     }
 }
 void MainWindow::newConnection(const QString& port, const QMap<QString, QVariant>& profile)
 {
-    const int tabs = ui->tabWidget->count();
+    const int tabs = m_instances->count();
     if(tabs == 1){
-        auto instance = qobject_cast<AtCoreInstanceWidget*>(ui->tabWidget->currentWidget());
+        auto instance = qobject_cast<AtCoreInstanceWidget*>(m_instances->currentWidget());
         if(!instance->connected()){
             instance->startConnection(port, profile);
-            ui->tabWidget->setTabText(ui->tabWidget->currentIndex(), profile["name"].toString());
+            m_instances->setTabText(m_instances->currentIndex(), profile["name"].toString());
             return;
         }
     }
     auto newInstanceWidget = new AtCoreInstanceWidget();
-    ui->tabWidget->addTab(newInstanceWidget, profile["name"].toString());
+    m_instances->addTab(newInstanceWidget, profile["name"].toString());
     newInstanceWidget->startConnection(port, profile);
 }
diff --git a/src/mainwindow.ui b/src/mainwindow.ui
--- a/src/mainwindow.ui
+++ b/src/mainwindow.ui
@@ -6,134 +6,21 @@
    <rect>
     <x>0</x>
     <y>0</y>
-    <width>484</width>
-    <height>446</height>
+    <width>1074</width>
+    <height>833</height>
    </rect>
   </property>
   <property name="windowTitle">
    <string>Atelier</string>
   </property>
-  <widget class="QWidget" name="centralwidget">
-   <layout class="QGridLayout" name="gridLayout">
-    <item row="0" column="0">
-     <widget class="QToolBox" name="toolBox">
-      <property name="currentIndex">
-       <number>0</number>
-      </property>
-      <widget class="Viewer3D" name="view3DWidget">
-       <property name="geometry">
-        <rect>
-         <x>0</x>
-         <y>0</y>
-         <width>233</width>
-         <height>285</height>
-        </rect>
-       </property>
-       <attribute name="label">
-        <string>Page 1</string>
-       </attribute>
-      </widget>
-      <widget class="VideoMonitorWidget" name="videoMonitorWidget">
-       <attribute name="label">
-        <string>Page</string>
-       </attribute>
-      </widget>
-      <widget class="GCodeEditorWidget" name="gcodeEditorWidget">
-       <property name="geometry">
-        <rect>
-         <x>0</x>
-         <y>0</y>
-         <width>233</width>
-         <height>285</height>
-        </rect>
-       </property>
-       <attribute name="label">
-        <string>Page 2</string>
-       </attribute>
-      </widget>
-     </widget>
-    </item>
-    <item row="0" column="1">
-     <widget class="QTabWidget" name="tabWidget">
-      <property name="currentIndex">
-       <number>0</number>
-      </property>
-      <widget class="AtCoreInstanceWidget" name="tab">
-       <attribute name="title">
-        <string>Tab 1</string>
-       </attribute>
-      </widget>
-     </widget>
-    </item>
-   </layout>
-   <widget class="QWidget" name="statusBarWidget" native="true">
-    <property name="geometry">
-     <rect>
-      <x>6</x>
-      <y>418</y>
-      <width>801</width>
-      <height>46</height>
-     </rect>
-    </property>
-    <property name="sizePolicy">
-     <sizepolicy hsizetype="Expanding" vsizetype="Fixed">
-      <horstretch>100</horstretch>
-      <verstretch>0</verstretch>
-     </sizepolicy>
-    </property>
-    <layout class="QHBoxLayout" name="horizontalLayout_2">
-     <property name="leftMargin">
-      <number>0</number>
-     </property>
-     <property name="topMargin">
-      <number>0</number>
-     </property>
-     <property name="rightMargin">
-      <number>0</number>
-     </property>
-     <property name="bottomMargin">
-      <number>0</number>
-     </property>
-     <item>
-      <widget class="QLabel" name="label_9">
-       <property name="text">
-        <string>Printer State:</string>
-       </property>
-      </widget>
-     </item>
-     <item>
-      <widget class="QLabel" name="lblState">
-       <property name="text">
-        <string>Not Connected</string>
-       </property>
-      </widget>
-     </item>
-     <item>
-      <spacer name="horizontalSpacer">
-       <property name="orientation">
-        <enum>Qt::Horizontal</enum>
-       </property>
-       <property name="sizeType">
-        <enum>QSizePolicy::Expanding</enum>
-       </property>
-       <property name="sizeHint" stdset="0">
-        <size>
-         <width>0</width>
-         <height>0</height>
-        </size>
-       </property>
-      </spacer>
-     </item>
-    </layout>
-   </widget>
-  </widget>
+  <widget class="QWidget" name="centralwidget"/>
   <widget class="QMenuBar" name="menubar">
    <property name="geometry">
     <rect>
      <x>0</x>
      <y>0</y>
-     <width>484</width>
-     <height>30</height>
+     <width>1074</width>
+     <height>36</height>
     </rect>
    </property>
    <widget class="QMenu" name="menuFile">
@@ -157,33 +44,12 @@
     <bool>false</bool>
    </property>
   </widget>
+  <action name="actionTeste">
+   <property name="text">
+    <string>Teste</string>
+   </property>
+  </action>
  </widget>
- <customwidgets>
-  <customwidget>
-   <class>GCodeEditorWidget</class>
-   <extends>QWidget</extends>
-   <header>widgets/gcodeeditorwidget.h</header>
-   <container>1</container>
-  </customwidget>
-  <customwidget>
-   <class>Viewer3D</class>
-   <extends>QWidget</extends>
-   <header>widgets/3dview/viewer3d.h</header>
-   <container>1</container>
-  </customwidget>
-  <customwidget>
-   <class>VideoMonitorWidget</class>
-   <extends>QWidget</extends>
-   <header>widgets/videomonitorwidget.h</header>
-   <container>1</container>
-  </customwidget>
-  <customwidget>
-   <class>AtCoreInstanceWidget</class>
-   <extends>QWidget</extends>
-   <header>widgets/atcoreinstancewidget.h</header>
-   <container>1</container>
-  </customwidget>
- </customwidgets>
  <resources/>
  <connections/>
 </ui>