diff --git a/Kernel/Makefile b/Kernel/Makefile
index db6f6e5217..3f3f73d036 100644
--- a/Kernel/Makefile
+++ b/Kernel/Makefile
@@ -66,6 +66,7 @@ WINDOWSERVER_OBJS = \
     ../WindowServer/WSMenuBar.o \
     ../WindowServer/WSMenu.o \
     ../WindowServer/WSMenuItem.o \
+    ../WindowServer/WSClientConnection.o \
     ../WindowServer/main.o
 
 AK_OBJS = \
diff --git a/Kernel/ProcessGUI.cpp b/Kernel/ProcessGUI.cpp
index cfdfff3269..4c87cd7146 100644
--- a/Kernel/ProcessGUI.cpp
+++ b/Kernel/ProcessGUI.cpp
@@ -20,6 +20,7 @@ void Process::destroy_all_windows()
 {
     if (!WSMessageLoop::the().running())
         return;
+    dbgprintf("Sending death notification for client_id %d\n", gui_client_id());
     WSMessageLoop::the().notify_client_died(gui_client_id());
 }
 
diff --git a/WindowServer/WSClientConnection.cpp b/WindowServer/WSClientConnection.cpp
new file mode 100644
index 0000000000..ff780e73e3
--- /dev/null
+++ b/WindowServer/WSClientConnection.cpp
@@ -0,0 +1,316 @@
+#include <WindowServer/WSClientConnection.h>
+#include <WindowServer/WSMessageLoop.h>
+#include <WindowServer/WSMenuBar.h>
+#include <WindowServer/WSMenu.h>
+#include <WindowServer/WSMenuItem.h>
+#include <WindowServer/WSWindow.h>
+#include <WindowServer/WSWindowManager.h>
+#include <Kernel/GUITypes.h>
+#include <Kernel/MemoryManager.h>
+
+Lockable<HashMap<int, WSClientConnection*>>* s_connections;
+
+
+WSClientConnection* WSClientConnection::from_client_id(int client_id)
+{
+    if (!s_connections)
+        return nullptr;
+    LOCKER(s_connections->lock());
+    auto it = s_connections->resource().find(client_id);
+    if (it == s_connections->resource().end())
+        return nullptr;
+    return (*it).value;
+}
+
+WSClientConnection* WSClientConnection::ensure_for_client_id(int client_id)
+{
+    if (auto* client = from_client_id(client_id))
+        return client;
+    return new WSClientConnection(client_id);
+}
+
+WSClientConnection::WSClientConnection(int client_id)
+    : m_client_id(client_id)
+{
+    if (!s_connections)
+        s_connections = new Lockable<HashMap<int, WSClientConnection*>>;
+    LOCKER(s_connections->lock());
+    s_connections->resource().set(client_id, this);
+
+    m_process = ((Process*)m_client_id)->make_weak_ptr();
+}
+
+WSClientConnection::~WSClientConnection()
+{
+    LOCKER(s_connections->lock());
+    s_connections->resource().remove(m_client_id);
+}
+
+void WSClientConnection::on_message(WSMessage& message)
+{
+    if (message.is_client_request()) {
+        handle_client_request(static_cast<WSAPIClientRequest&>(message));
+        return;
+    }
+
+    if (message.type() == WSMessage::WM_ClientDisconnected) {
+        int client_id = static_cast<WSClientDisconnectedNotification&>(message).client_id();
+        dbgprintf("WSClientConnection: Client disconnected: %d\n", client_id);
+        delete this;
+        return;
+    }
+}
+
+void WSClientConnection::handle_client_request(WSAPIClientRequest& request)
+{
+    switch (request.type()) {
+    case WSMessage::APICreateMenubarRequest: {
+        int menubar_id = m_next_menubar_id++;
+        auto menubar = make<WSMenuBar>(menubar_id, *WSMessageLoop::process_from_client_id(request.client_id()));
+        m_menubars.set(menubar_id, move(menubar));
+        GUI_ServerMessage response;
+        response.type = GUI_ServerMessage::Type::DidCreateMenubar;
+        response.menu.menubar_id = menubar_id;
+        WSMessageLoop::the().post_message_to_client(request.client_id(), response);
+        break;
+    }
+    case WSMessage::APIDestroyMenubarRequest: {
+        int menubar_id = static_cast<WSAPIDestroyMenubarRequest&>(request).menubar_id();
+        auto it = m_menubars.find(menubar_id);
+        if (it == m_menubars.end()) {
+            ASSERT_NOT_REACHED();
+            // FIXME: Send an error.
+            return;
+        }
+        auto& menubar = *(*it).value;
+        WSWindowManager::the().close_menubar(menubar);
+        m_menubars.remove(it);
+        GUI_ServerMessage response;
+        response.type = GUI_ServerMessage::Type::DidDestroyMenubar;
+        response.menu.menubar_id = menubar_id;
+        WSMessageLoop::the().post_message_to_client(request.client_id(), response);
+        break;
+    }
+    case WSMessage::APICreateMenuRequest: {
+        int menu_id = m_next_menu_id++;
+        auto menu = make<WSMenu>(*WSMessageLoop::process_from_client_id(request.client_id()), menu_id, static_cast<WSAPICreateMenuRequest&>(request).text());
+        m_menus.set(menu_id, move(menu));
+        GUI_ServerMessage response;
+        response.type = GUI_ServerMessage::Type::DidCreateMenu;
+        response.menu.menu_id = menu_id;
+        WSMessageLoop::the().post_message_to_client(request.client_id(), response);
+        break;
+    }
+    case WSMessage::APIDestroyMenuRequest: {
+        int menu_id = static_cast<WSAPIDestroyMenuRequest&>(request).menu_id();
+        auto it = m_menus.find(menu_id);
+        if (it == m_menus.end()) {
+            ASSERT_NOT_REACHED();
+            // FIXME: Send an error.
+            return;
+        }
+        auto& menu = *(*it).value;
+        WSWindowManager::the().close_menu(menu);
+        m_menus.remove(it);
+        GUI_ServerMessage response;
+        response.type = GUI_ServerMessage::Type::DidDestroyMenu;
+        response.menu.menu_id = menu_id;
+        WSMessageLoop::the().post_message_to_client(request.client_id(), response);
+        break;
+    }
+    case WSMessage::APISetApplicationMenubarRequest: {
+        int menubar_id = static_cast<WSAPISetApplicationMenubarRequest&>(request).menubar_id();
+        auto it = m_menubars.find(menubar_id);
+        if (it == m_menubars.end()) {
+            ASSERT_NOT_REACHED();
+            // FIXME: Send an error.
+            return;
+        }
+        auto& menubar = *(*it).value;
+        m_app_menubar = menubar.make_weak_ptr();
+        WSWindowManager::the().notify_client_changed_app_menubar(*this);
+        GUI_ServerMessage response;
+        response.type = GUI_ServerMessage::Type::DidSetApplicationMenubar;
+        response.menu.menubar_id = menubar_id;
+        WSMessageLoop::the().post_message_to_client(request.client_id(), response);
+        break;
+    }
+    case WSMessage::APIAddMenuToMenubarRequest: {
+        int menubar_id = static_cast<WSAPIAddMenuToMenubarRequest&>(request).menubar_id();
+        int menu_id = static_cast<WSAPIAddMenuToMenubarRequest&>(request).menu_id();
+        auto it = m_menubars.find(menubar_id);
+        auto jt = m_menus.find(menu_id);
+        if (it == m_menubars.end() || jt == m_menus.end()) {
+            ASSERT_NOT_REACHED();
+        }
+        auto& menubar = *(*it).value;
+        auto& menu = *(*jt).value;
+        menubar.add_menu(&menu);
+        GUI_ServerMessage response;
+        response.type = GUI_ServerMessage::Type::DidAddMenuToMenubar;
+        response.menu.menubar_id = menubar_id;
+        response.menu.menu_id = menu_id;
+        WSMessageLoop::the().post_message_to_client(request.client_id(), response);
+        break;
+    }
+    case WSMessage::APIAddMenuItemRequest: {
+        int menu_id = static_cast<WSAPIAddMenuItemRequest&>(request).menu_id();
+        unsigned identifier = static_cast<WSAPIAddMenuItemRequest&>(request).identifier();
+        String text = static_cast<WSAPIAddMenuItemRequest&>(request).text();
+        auto it = m_menus.find(menu_id);
+        if (it == m_menus.end()) {
+            ASSERT_NOT_REACHED();
+        }
+        auto& menu = *(*it).value;
+        menu.add_item(make<WSMenuItem>(identifier, move(text)));
+        GUI_ServerMessage response;
+        response.type = GUI_ServerMessage::Type::DidAddMenuItem;
+        response.menu.menu_id = menu_id;
+        response.menu.identifier = identifier;
+        WSMessageLoop::the().post_message_to_client(request.client_id(), response);
+        break;
+    }
+    case WSMessage::APIAddMenuSeparatorRequest: {
+        int menu_id = static_cast<WSAPIAddMenuSeparatorRequest&>(request).menu_id();
+        auto it = m_menus.find(menu_id);
+        if (it == m_menus.end()) {
+            ASSERT_NOT_REACHED();
+        }
+        auto& menu = *(*it).value;
+        menu.add_item(make<WSMenuItem>(WSMenuItem::Separator));
+        GUI_ServerMessage response;
+        response.type = GUI_ServerMessage::Type::DidAddMenuSeparator;
+        response.menu.menu_id = menu_id;
+        WSMessageLoop::the().post_message_to_client(request.client_id(), response);
+        break;
+    }
+    case WSMessage::APISetWindowTitleRequest: {
+        int window_id = static_cast<WSAPISetWindowTitleRequest&>(request).window_id();
+        auto it = m_windows.find(window_id);
+        if (it == m_windows.end()) {
+            ASSERT_NOT_REACHED();
+        }
+        auto& window = *(*it).value;
+        window.set_title(static_cast<WSAPISetWindowTitleRequest&>(request).title());
+        break;
+    }
+    case WSMessage::APIGetWindowTitleRequest: {
+        int window_id = static_cast<WSAPIGetWindowTitleRequest&>(request).window_id();
+        auto it = m_windows.find(window_id);
+        if (it == m_windows.end()) {
+            ASSERT_NOT_REACHED();
+        }
+        auto& window = *(*it).value;
+        GUI_ServerMessage response;
+        response.type = GUI_ServerMessage::Type::DidGetWindowTitle;
+        response.window_id = window.window_id();
+        ASSERT(window.title().length() < sizeof(response.text));
+        strcpy(response.text, window.title().characters());
+        response.text_length = window.title().length();
+        WSMessageLoop::the().post_message_to_client(request.client_id(), response);
+        break;
+    }
+    case WSMessage::APISetWindowRectRequest: {
+        int window_id = static_cast<WSAPISetWindowRectRequest&>(request).window_id();
+        auto it = m_windows.find(window_id);
+        if (it == m_windows.end()) {
+            ASSERT_NOT_REACHED();
+        }
+        auto& window = *(*it).value;
+        window.set_rect(static_cast<WSAPISetWindowRectRequest&>(request).rect());
+        break;
+    }
+    case WSMessage::APIGetWindowRectRequest: {
+        int window_id = static_cast<WSAPIGetWindowRectRequest&>(request).window_id();
+        auto it = m_windows.find(window_id);
+        if (it == m_windows.end()) {
+            ASSERT_NOT_REACHED();
+        }
+        auto& window = *(*it).value;
+        GUI_ServerMessage response;
+        response.type = GUI_ServerMessage::Type::DidGetWindowRect;
+        response.window_id = window.window_id();
+        response.window.rect = window.rect();
+        WSMessageLoop::the().post_message_to_client(request.client_id(), response);
+        break;
+    }
+    case WSMessage::APICreateWindowRequest: {
+        int window_id = m_next_window_id++;
+        auto window = make<WSWindow>(request.client_id(), window_id);
+        window->set_title(static_cast<WSAPICreateWindowRequest&>(request).title());
+        window->set_rect(static_cast<WSAPICreateWindowRequest&>(request).rect());
+        m_windows.set(window_id, move(window));
+        GUI_ServerMessage response;
+        response.type = GUI_ServerMessage::Type::DidCreateWindow;
+        response.window_id = window_id;
+        WSMessageLoop::the().post_message_to_client(request.client_id(), response);
+        break;
+    }
+    case WSMessage::APIDestroyWindowRequest: {
+        int window_id = static_cast<WSAPIGetWindowRectRequest&>(request).window_id();
+        auto it = m_windows.find(window_id);
+        if (it == m_windows.end()) {
+            ASSERT_NOT_REACHED();
+        }
+        auto& window = *(*it).value;
+        WSWindowManager::the().invalidate(window);
+        m_windows.remove(it);
+        break;
+    }
+    case WSMessage::APIInvalidateRectRequest: {
+        int window_id = static_cast<WSAPIInvalidateRectRequest&>(request).window_id();
+        auto it = m_windows.find(window_id);
+        if (it == m_windows.end()) {
+            ASSERT_NOT_REACHED();
+        }
+        GUI_ServerMessage response;
+        response.type = GUI_ServerMessage::Type::Paint;
+        response.window_id = window_id;
+        response.paint.rect = static_cast<WSAPIInvalidateRectRequest&>(request).rect();
+        WSMessageLoop::the().post_message_to_client(request.client_id(), response);
+        break;
+    }
+    case WSMessage::APIDidFinishPaintingNotification: {
+        int window_id = static_cast<WSAPIDidFinishPaintingNotification&>(request).window_id();
+        auto it = m_windows.find(window_id);
+        if (it == m_windows.end()) {
+            ASSERT_NOT_REACHED();
+        }
+        auto& window = *(*it).value;
+        WSWindowManager::the().invalidate(window, static_cast<WSAPIDidFinishPaintingNotification&>(request).rect());
+        break;
+    }
+    case WSMessage::APIGetWindowBackingStoreRequest: {
+        int window_id = static_cast<WSAPIGetWindowBackingStoreRequest&>(request).window_id();
+        auto it = m_windows.find(window_id);
+        if (it == m_windows.end()) {
+            ASSERT_NOT_REACHED();
+        }
+        auto& window = *(*it).value;
+        auto* backing_store = window.backing();
+
+        // FIXME: It shouldn't work this way!
+        backing_store->retain();
+
+        GUI_ServerMessage response;
+        response.type = GUI_ServerMessage::Type::DidGetWindowBackingStore;
+        response.window_id = window_id;
+        response.backing.backing_store_id = backing_store;
+        response.backing.bpp = sizeof(RGBA32);
+        response.backing.pitch = backing_store->pitch();
+        response.backing.size = backing_store->size();
+        response.backing.pixels = reinterpret_cast<RGBA32*>(backing_store->client_region()->laddr().as_ptr());
+        WSMessageLoop::the().post_message_to_client(request.client_id(), response);
+        break;
+    }
+    case WSMessage::APIReleaseWindowBackingStoreRequest: {
+        int backing_store_id = static_cast<WSAPIReleaseWindowBackingStoreRequest&>(request).backing_store_id();
+        // FIXME: It shouldn't work this way!
+        auto* backing_store = (GraphicsBitmap*)backing_store_id;
+        backing_store->release();
+        break;
+    }
+    default:
+        break;
+    }
+}
diff --git a/WindowServer/WSClientConnection.h b/WindowServer/WSClientConnection.h
new file mode 100644
index 0000000000..529447c469
--- /dev/null
+++ b/WindowServer/WSClientConnection.h
@@ -0,0 +1,48 @@
+#pragma once
+
+#include <AK/HashMap.h>
+#include <AK/OwnPtr.h>
+#include <AK/WeakPtr.h>
+#include <WindowServer/WSMessageReceiver.h>
+
+class WSWindow;
+class WSMenu;
+class WSMenuBar;
+class WSAPIClientRequest;
+
+// FIXME: Remove.
+class Process;
+
+class WSClientConnection final : public WSMessageReceiver {
+public:
+    explicit WSClientConnection(int client_id);
+    virtual ~WSClientConnection() override;
+
+    static WSClientConnection* from_client_id(int client_id);
+    static WSClientConnection* ensure_for_client_id(int client_id);
+
+    // FIXME: Remove.
+    Process* process() { return m_process.ptr(); }
+
+    int client_id() const { return m_client_id; }
+    WSMenuBar* app_menubar() { return m_app_menubar.ptr(); }
+
+private:
+    virtual void on_message(WSMessage&) override;
+
+    void handle_client_request(WSAPIClientRequest&);
+
+    int m_client_id { 0 };
+
+    HashMap<int, OwnPtr<WSWindow>> m_windows;
+    HashMap<int, OwnPtr<WSMenuBar>> m_menubars;
+    HashMap<int, OwnPtr<WSMenu>> m_menus;
+    WeakPtr<WSMenuBar> m_app_menubar;
+
+    int m_next_menubar_id { 10000 };
+    int m_next_menu_id { 20000 };
+    int m_next_window_id { 1982 };
+
+    // FIXME: Remove.
+    WeakPtr<Process> m_process;
+};
diff --git a/WindowServer/WSMenu.h b/WindowServer/WSMenu.h
index bd15d02e59..363f92b52c 100644
--- a/WindowServer/WSMenu.h
+++ b/WindowServer/WSMenu.h
@@ -12,7 +12,7 @@ class WSWindow;
 class Font;
 class Process;
 
-class WSMenu {
+class WSMenu : public Weakable<WSMenu> {
 public:
     WSMenu(Process&, int menu_id, String&& name);
     ~WSMenu();
diff --git a/WindowServer/WSMenuBar.h b/WindowServer/WSMenuBar.h
index 2aec358889..285aa8d067 100644
--- a/WindowServer/WSMenuBar.h
+++ b/WindowServer/WSMenuBar.h
@@ -2,11 +2,12 @@
 
 #include "WSMenu.h"
 #include <AK/Vector.h>
+#include <AK/Weakable.h>
 #include <AK/WeakPtr.h>
 
 class Process;
 
-class WSMenuBar {
+class WSMenuBar : public Weakable<WSMenuBar> {
 public:
     WSMenuBar(int menubar_id, Process&);
     ~WSMenuBar();
diff --git a/WindowServer/WSMessageLoop.cpp b/WindowServer/WSMessageLoop.cpp
index 4493e8e382..40b3cb1a16 100644
--- a/WindowServer/WSMessageLoop.cpp
+++ b/WindowServer/WSMessageLoop.cpp
@@ -3,6 +3,7 @@
 #include "WSMessageReceiver.h"
 #include "WSWindowManager.h"
 #include "WSScreen.h"
+#include <WindowServer/WSClientConnection.h>
 #include "PS2MouseDevice.h"
 #include <Kernel/Keyboard.h>
 #include <AK/Bitmap.h>
@@ -267,7 +268,10 @@ void WSMessageLoop::drain_keyboard()
 void WSMessageLoop::notify_client_died(int client_id)
 {
     LOCKER(m_lock);
-    post_message(&WSWindowManager::the(), make<WSClientDisconnectedNotification>(client_id));
+    auto* client = WSClientConnection::from_client_id(client_id);
+    if (!client)
+        return;
+    post_message(client, make<WSClientDisconnectedNotification>(client_id));
 }
 
 ssize_t WSMessageLoop::on_receive_from_client(int client_id, const byte* data, size_t size)
@@ -277,67 +281,70 @@ ssize_t WSMessageLoop::on_receive_from_client(int client_id, const byte* data, s
         Scheduler::yield();
 
     LOCKER(m_lock);
+
+    WSClientConnection* client = WSClientConnection::ensure_for_client_id(client_id);
+
     ASSERT(size == sizeof(GUI_ClientMessage));
     auto& message = *reinterpret_cast<const GUI_ClientMessage*>(data);
     switch (message.type) {
     case GUI_ClientMessage::Type::CreateMenubar:
-        post_message(&WSWindowManager::the(), make<WSAPICreateMenubarRequest>(client_id));
+        post_message(client, make<WSAPICreateMenubarRequest>(client_id));
         break;
     case GUI_ClientMessage::Type::DestroyMenubar:
-        post_message(&WSWindowManager::the(), make<WSAPIDestroyMenubarRequest>(client_id, message.menu.menubar_id));
+        post_message(client, make<WSAPIDestroyMenubarRequest>(client_id, message.menu.menubar_id));
         break;
     case GUI_ClientMessage::Type::SetApplicationMenubar:
-        post_message(&WSWindowManager::the(), make<WSAPISetApplicationMenubarRequest>(client_id, message.menu.menubar_id));
+        post_message(client, make<WSAPISetApplicationMenubarRequest>(client_id, message.menu.menubar_id));
         break;
     case GUI_ClientMessage::Type::AddMenuToMenubar:
-        post_message(&WSWindowManager::the(), make<WSAPIAddMenuToMenubarRequest>(client_id, message.menu.menubar_id, message.menu.menu_id));
+        post_message(client, make<WSAPIAddMenuToMenubarRequest>(client_id, message.menu.menubar_id, message.menu.menu_id));
         break;
     case GUI_ClientMessage::Type::CreateMenu:
         ASSERT(message.text_length < sizeof(message.text));
-        post_message(&WSWindowManager::the(), make<WSAPICreateMenuRequest>(client_id, String(message.text, message.text_length)));
+        post_message(client, make<WSAPICreateMenuRequest>(client_id, String(message.text, message.text_length)));
         break;
     case GUI_ClientMessage::Type::DestroyMenu:
-        post_message(&WSWindowManager::the(), make<WSAPIDestroyMenuRequest>(client_id, message.menu.menu_id));
+        post_message(client, make<WSAPIDestroyMenuRequest>(client_id, message.menu.menu_id));
         break;
     case GUI_ClientMessage::Type::AddMenuItem:
         ASSERT(message.text_length < sizeof(message.text));
-        post_message(&WSWindowManager::the(), make<WSAPIAddMenuItemRequest>(client_id, message.menu.menu_id, message.menu.identifier, String(message.text, message.text_length)));
+        post_message(client, make<WSAPIAddMenuItemRequest>(client_id, message.menu.menu_id, message.menu.identifier, String(message.text, message.text_length)));
         break;
     case GUI_ClientMessage::Type::CreateWindow:
         ASSERT(message.text_length < sizeof(message.text));
-        post_message(&WSWindowManager::the(), make<WSAPICreateWindowRequest>(client_id, message.window.rect, String(message.text, message.text_length)));
+        post_message(client, make<WSAPICreateWindowRequest>(client_id, message.window.rect, String(message.text, message.text_length)));
         break;
     case GUI_ClientMessage::Type::DestroyWindow:
-        post_message(&WSWindowManager::the(), make<WSAPIDestroyWindowRequest>(client_id, message.window_id));
+        post_message(client, make<WSAPIDestroyWindowRequest>(client_id, message.window_id));
         break;
     case GUI_ClientMessage::Type::SetWindowTitle:
         ASSERT(message.text_length < sizeof(message.text));
-        post_message(&WSWindowManager::the(), make<WSAPISetWindowTitleRequest>(client_id, message.window_id, String(message.text, message.text_length)));
+        post_message(client, make<WSAPISetWindowTitleRequest>(client_id, message.window_id, String(message.text, message.text_length)));
         break;
     case GUI_ClientMessage::Type::GetWindowTitle:
         ASSERT(message.text_length < sizeof(message.text));
-        post_message(&WSWindowManager::the(), make<WSAPIGetWindowTitleRequest>(client_id, message.window_id));
+        post_message(client, make<WSAPIGetWindowTitleRequest>(client_id, message.window_id));
         break;
     case GUI_ClientMessage::Type::SetWindowRect:
-        post_message(&WSWindowManager::the(), make<WSAPISetWindowRectRequest>(client_id, message.window_id, message.window.rect));
+        post_message(client, make<WSAPISetWindowRectRequest>(client_id, message.window_id, message.window.rect));
         break;
     case GUI_ClientMessage::Type::GetWindowRect:
-        post_message(&WSWindowManager::the(), make<WSAPIGetWindowRectRequest>(client_id, message.window_id));
+        post_message(client, make<WSAPIGetWindowRectRequest>(client_id, message.window_id));
         break;
     case GUI_ClientMessage::Type::InvalidateRect:
-        post_message(&WSWindowManager::the(), make<WSAPIInvalidateRectRequest>(client_id, message.window_id, message.window.rect));
+        post_message(client, make<WSAPIInvalidateRectRequest>(client_id, message.window_id, message.window.rect));
         break;
     case GUI_ClientMessage::Type::DidFinishPainting:
-        post_message(&WSWindowManager::the(), make<WSAPIDidFinishPaintingNotification>(client_id, message.window_id, message.window.rect));
+        post_message(client, make<WSAPIDidFinishPaintingNotification>(client_id, message.window_id, message.window.rect));
         break;
     case GUI_ClientMessage::Type::GetWindowBackingStore:
-        post_message(&WSWindowManager::the(), make<WSAPIGetWindowBackingStoreRequest>(client_id, message.window_id));
+        post_message(client, make<WSAPIGetWindowBackingStoreRequest>(client_id, message.window_id));
         break;
     case GUI_ClientMessage::Type::ReleaseWindowBackingStore:
-        post_message(&WSWindowManager::the(), make<WSAPIReleaseWindowBackingStoreRequest>(client_id, (int)message.backing.backing_store_id));
+        post_message(client, make<WSAPIReleaseWindowBackingStoreRequest>(client_id, (int)message.backing.backing_store_id));
         break;
     case GUI_ClientMessage::Type::SetGlobalCursorTracking:
-        post_message(&WSWindowManager::the(), make<WSAPISetGlobalCursorTrackingRequest>(client_id, message.value));
+        post_message(client, make<WSAPISetGlobalCursorTrackingRequest>(client_id, message.value));
         break;
     }
     server_process().request_wakeup();
diff --git a/WindowServer/WSWindow.cpp b/WindowServer/WSWindow.cpp
index 07c933c522..bea91954dd 100644
--- a/WindowServer/WSWindow.cpp
+++ b/WindowServer/WSWindow.cpp
@@ -3,6 +3,7 @@
 #include "WSMessage.h"
 #include "WSMessageLoop.h"
 #include "Process.h"
+#include <WindowServer/WSClientConnection.h>
 
 WSWindow::WSWindow(WSMenu& menu)
     : m_lock("WSWindow (menu)")
@@ -12,12 +13,11 @@ WSWindow::WSWindow(WSMenu& menu)
     WSWindowManager::the().add_window(*this);
 }
 
-WSWindow::WSWindow(Process& process, int window_id)
+WSWindow::WSWindow(int client_id, int window_id)
     : m_lock("WSWindow (normal)")
+    , m_client_id(client_id)
     , m_type(WSWindowType::Normal)
-    , m_process(&process)
     , m_window_id(window_id)
-    , m_pid(process.pid())
 {
     WSWindowManager::the().add_window(*this);
 }
@@ -44,15 +44,21 @@ void WSWindow::set_rect(const Rect& rect)
     Rect old_rect;
     {
         WSWindowLocker locker(*this);
-        if (!m_process && !m_menu)
+
+        Process* process = nullptr;
+        auto* client = WSClientConnection::from_client_id(m_client_id);
+        if (client)
+            process = client->process();
+
+        if (!process && !m_menu)
             return;
         if (m_rect == rect)
             return;
         old_rect = m_rect;
         m_rect = rect;
         if (!m_backing || old_rect.size() != rect.size()) {
-            if (m_process)
-                m_backing = GraphicsBitmap::create(*m_process, m_rect.size());
+            if (process)
+                m_backing = GraphicsBitmap::create(*process, m_rect.size());
             if (m_menu)
                 m_backing = GraphicsBitmap::create_kernel_only(m_rect.size());
         }
@@ -135,19 +141,15 @@ void WSWindow::on_message(WSMessage& message)
 
     {
         WSWindowLocker window_locker(*this);
-        if (!m_process)
-            return;
-        LOCKER(m_process->gui_events_lock());
-        m_process->gui_events().append(move(gui_event));
+        if (auto* client = WSClientConnection::from_client_id(m_client_id)) {
+            if (auto* process = client->process()) {
+                LOCKER(process->gui_events_lock());
+                process->gui_events().append(move(gui_event));
+            }
+        }
     }
 }
 
-void WSWindow::notify_process_died(Badge<Process>)
-{
-    WSWindowLocker locker(*this);
-    m_process = nullptr;
-}
-
 void WSWindow::set_global_cursor_tracking_enabled(bool enabled)
 {
     dbgprintf("WSWindow{%p} global_cursor_tracking <- %u\n", enabled);
diff --git a/WindowServer/WSWindow.h b/WindowServer/WSWindow.h
index db5e148a77..ff8c7de012 100644
--- a/WindowServer/WSWindow.h
+++ b/WindowServer/WSWindow.h
@@ -6,21 +6,19 @@
 #include <AK/InlineLinkedList.h>
 #include <AK/Lock.h>
 #include <AK/Badge.h>
-#include <Kernel/Process.h>
 #include "WSMessageReceiver.h"
 #include <WindowServer/WSWindowType.h>
 
-class Process;
 class WSMenu;
 
 class WSWindow final : public WSMessageReceiver, public InlineLinkedListNode<WSWindow> {
     friend class WSWindowLocker;
 public:
-    WSWindow(Process&, int window_id);
+    WSWindow(int client_id, int window_id);
     explicit WSWindow(WSMenu&);
     virtual ~WSWindow() override;
 
-    const Process* process() const { return m_process; }
+    int client_id() const { return m_client_id; }
 
     WSWindowType type() const { return m_type; }
     int window_id() const { return m_window_id; }
@@ -59,13 +57,9 @@ public:
 
     GraphicsBitmap* backing() { return m_backing.ptr(); }
 
-    pid_t pid() const { return m_pid; }
-
     void set_global_cursor_tracking_enabled(bool);
     bool global_cursor_tracking() const { return m_global_cursor_tracking_enabled; }
 
-    void notify_process_died(Badge<Process>);
-
     // For InlineLinkedList.
     // FIXME: Maybe make a ListHashSet and then WSWindowManager can just use that.
     WSWindow* m_next { nullptr };
@@ -73,6 +67,7 @@ public:
 
 private:
     Lock m_lock;
+    int m_client_id { 0 };
     String m_title;
     Rect m_rect;
     WSWindowType m_type { WSWindowType::Normal };
@@ -83,9 +78,7 @@ private:
     WSMenu* m_menu { nullptr };
 
     RetainPtr<GraphicsBitmap> m_backing;
-    Process* m_process { nullptr };
     int m_window_id { -1 };
-    pid_t m_pid { -1 };
 };
 
 class WSWindowLocker {
diff --git a/WindowServer/WSWindowManager.cpp b/WindowServer/WSWindowManager.cpp
index eb2196f7f9..ca46ed2323 100644
--- a/WindowServer/WSWindowManager.cpp
+++ b/WindowServer/WSWindowManager.cpp
@@ -14,6 +14,7 @@
 #include "WSMenu.h"
 #include "WSMenuBar.h"
 #include "WSMenuItem.h"
+#include <WindowServer/WSClientConnection.h>
 #include <Kernel/RTC.h>
 
 //#define DEBUG_COUNTERS
@@ -239,7 +240,10 @@ int WSWindowManager::menubar_menu_margin() const
 void WSWindowManager::set_current_menubar(WSMenuBar* menubar)
 {
     LOCKER(m_lock);
-    m_current_menubar = menubar;
+    if (menubar)
+        m_current_menubar = menubar->make_weak_ptr();
+    else
+        m_current_menubar = nullptr;
     dbgprintf("[WM] Current menubar is now %p\n", menubar);
     Point next_menu_location { menubar_menu_margin() / 2, 3 };
     for_each_active_menubar_menu([&] (WSMenu& menu) {
@@ -395,10 +399,10 @@ void WSWindowManager::handle_menu_mouse_event(WSMenu& menu, WSMouseEvent& event)
 {
     bool is_hover_with_any_menu_open = event.type() == WSMouseEvent::MouseMove && m_current_menu;
     bool is_mousedown_with_left_button = event.type() == WSMouseEvent::MouseDown && event.button() == MouseButton::Left;
-    bool should_open_menu = &menu != m_current_menu && (is_hover_with_any_menu_open || is_mousedown_with_left_button);
+    bool should_open_menu = &menu != current_menu() && (is_hover_with_any_menu_open || is_mousedown_with_left_button);
 
     if (should_open_menu) {
-        if (m_current_menu == &menu)
+        if (current_menu() == &menu)
             return;
         close_current_menu();
         if (!menu.is_empty()) {
@@ -406,7 +410,7 @@ void WSWindowManager::handle_menu_mouse_event(WSMenu& menu, WSMouseEvent& event)
             menu_window.move_to({ menu.rect_in_menubar().x(), menu.rect_in_menubar().bottom() });
             menu_window.set_visible(true);
         }
-        m_current_menu = &menu;
+        m_current_menu = menu.make_weak_ptr();
         return;
     }
     if (event.type() == WSMouseEvent::MouseDown && event.button() == MouseButton::Left) {
@@ -422,7 +426,7 @@ void WSWindowManager::close_current_menu()
     m_current_menu = nullptr;
 }
 
-void WSWindowManager::handle_menubar_mouse_event(WSMenuBar&, WSMouseEvent& event)
+void WSWindowManager::handle_menubar_mouse_event(WSMouseEvent& event)
 {
     for_each_active_menubar_menu([&] (WSMenu& menu) {
         if (menu.rect_in_menubar().contains(event.position())) {
@@ -499,7 +503,7 @@ void WSWindowManager::process_mouse_event(WSMouseEvent& event)
     }
 
     if (menubar_rect().contains(event.position())) {
-        handle_menubar_mouse_event(*m_current_menubar, event);
+        handle_menubar_mouse_event(event);
         return;
     }
 
@@ -684,7 +688,7 @@ void WSWindowManager::draw_menubar()
     m_back_painter->draw_line({ 0, menubar_rect().bottom() }, { menubar_rect().right(), menubar_rect().bottom() }, Color::White);
     for_each_active_menubar_menu([&] (WSMenu& menu) {
         Color text_color = Color::Black;
-        if (&menu == m_current_menu) {
+        if (&menu == current_menu()) {
             m_back_painter->fill_rect(menu.rect_in_menubar(), menu_selection_color());
             text_color = Color::White;
         }
@@ -733,284 +737,6 @@ void WSWindowManager::on_message(WSMessage& message)
         compose();
         return;
     }
-
-    if (message.is_client_request()) {
-        handle_client_request(static_cast<WSAPIClientRequest&>(message));
-        return;
-    }
-
-    if (message.type() == WSMessage::WM_ClientDisconnected) {
-        int client_id = static_cast<WSClientDisconnectedNotification&>(message).client_id();
-        dbgprintf("[WM] Client disconnected: %d\n", client_id);
-
-        destroy_all_menus(*WSMessageLoop::process_from_client_id(client_id));
-        Vector<int> windows_belonging_to_client;
-        for (auto& it : m_windows_by_id) {
-            if (it.value->process()->gui_client_id() == client_id)
-                windows_belonging_to_client.append(it.value->window_id());
-        }
-        for (int window_id : windows_belonging_to_client) {
-            m_windows_by_id.remove(window_id);
-        }
-        return;
-    }
-}
-
-void WSWindowManager::handle_client_request(WSAPIClientRequest& request)
-{
-    switch (request.type()) {
-    case WSMessage::APICreateMenubarRequest: {
-        int menubar_id = m_next_menubar_id++;
-        auto menubar = make<WSMenuBar>(menubar_id, *WSMessageLoop::process_from_client_id(request.client_id()));
-        m_menubars.set(menubar_id, move(menubar));
-        GUI_ServerMessage response;
-        response.type = GUI_ServerMessage::Type::DidCreateMenubar;
-        response.menu.menubar_id = menubar_id;
-        WSMessageLoop::the().post_message_to_client(request.client_id(), response);
-        break;
-    }
-    case WSMessage::APIDestroyMenubarRequest: {
-        int menubar_id = static_cast<WSAPIDestroyMenubarRequest&>(request).menubar_id();
-        auto it = m_menubars.find(menubar_id);
-        if (it == m_menubars.end()) {
-            ASSERT_NOT_REACHED();
-            // FIXME: Send an error.
-            return;
-        }
-        auto& menubar = *(*it).value;
-        if (&menubar == m_current_menubar)
-            set_current_menubar(nullptr);
-        m_menubars.remove(it);
-        GUI_ServerMessage response;
-        response.type = GUI_ServerMessage::Type::DidDestroyMenubar;
-        response.menu.menubar_id = menubar_id;
-        WSMessageLoop::the().post_message_to_client(request.client_id(), response);
-        break;
-    }
-    case WSMessage::APICreateMenuRequest: {
-        int menu_id = m_next_menu_id++;
-        auto menu = make<WSMenu>(*WSMessageLoop::process_from_client_id(request.client_id()), menu_id, static_cast<WSAPICreateMenuRequest&>(request).text());
-        m_menus.set(menu_id, move(menu));
-        GUI_ServerMessage response;
-        response.type = GUI_ServerMessage::Type::DidCreateMenu;
-        response.menu.menu_id = menu_id;
-        WSMessageLoop::the().post_message_to_client(request.client_id(), response);
-        break;
-    }
-    case WSMessage::APIDestroyMenuRequest: {
-        int menu_id = static_cast<WSAPIDestroyMenuRequest&>(request).menu_id();
-        auto it = m_menus.find(menu_id);
-        if (it == m_menus.end()) {
-            ASSERT_NOT_REACHED();
-            // FIXME: Send an error.
-            return;
-        }
-        auto& menu = *(*it).value;
-        close_menu(menu);
-        m_menus.remove(it);
-        GUI_ServerMessage response;
-        response.type = GUI_ServerMessage::Type::DidDestroyMenu;
-        response.menu.menu_id = menu_id;
-        WSMessageLoop::the().post_message_to_client(request.client_id(), response);
-        break;
-    }
-    case WSMessage::APISetApplicationMenubarRequest: {
-        int menubar_id = static_cast<WSAPISetApplicationMenubarRequest&>(request).menubar_id();
-        auto it = m_menubars.find(menubar_id);
-        if (it == m_menubars.end()) {
-            ASSERT_NOT_REACHED();
-            // FIXME: Send an error.
-            return;
-        }
-        auto& menubar = *(*it).value;
-        m_app_menubars.set(request.client_id(), &menubar);
-        if (active_client_id() == request.client_id())
-            set_current_menubar(&menubar);
-        invalidate();
-        GUI_ServerMessage response;
-        response.type = GUI_ServerMessage::Type::DidSetApplicationMenubar;
-        response.menu.menubar_id = menubar_id;
-        WSMessageLoop::the().post_message_to_client(request.client_id(), response);
-        break;
-    }
-    case WSMessage::APIAddMenuToMenubarRequest: {
-        int menubar_id = static_cast<WSAPIAddMenuToMenubarRequest&>(request).menubar_id();
-        int menu_id = static_cast<WSAPIAddMenuToMenubarRequest&>(request).menu_id();
-        auto it = m_menubars.find(menubar_id);
-        auto jt = m_menus.find(menu_id);
-        if (it == m_menubars.end() || jt == m_menus.end()) {
-            ASSERT_NOT_REACHED();
-        }
-        auto& menubar = *(*it).value;
-        auto& menu = *(*jt).value;
-        menubar.add_menu(&menu);
-        GUI_ServerMessage response;
-        response.type = GUI_ServerMessage::Type::DidAddMenuToMenubar;
-        response.menu.menubar_id = menubar_id;
-        response.menu.menu_id = menu_id;
-        WSMessageLoop::the().post_message_to_client(request.client_id(), response);
-        break;
-    }
-    case WSMessage::APIAddMenuItemRequest: {
-        int menu_id = static_cast<WSAPIAddMenuItemRequest&>(request).menu_id();
-        unsigned identifier = static_cast<WSAPIAddMenuItemRequest&>(request).identifier();
-        String text = static_cast<WSAPIAddMenuItemRequest&>(request).text();
-        auto it = m_menus.find(menu_id);
-        if (it == m_menus.end()) {
-            ASSERT_NOT_REACHED();
-        }
-        auto& menu = *(*it).value;
-        menu.add_item(make<WSMenuItem>(identifier, move(text)));
-        GUI_ServerMessage response;
-        response.type = GUI_ServerMessage::Type::DidAddMenuItem;
-        response.menu.menu_id = menu_id;
-        response.menu.identifier = identifier;
-        WSMessageLoop::the().post_message_to_client(request.client_id(), response);
-        break;
-    }
-    case WSMessage::APIAddMenuSeparatorRequest: {
-        int menu_id = static_cast<WSAPIAddMenuSeparatorRequest&>(request).menu_id();
-        auto it = m_menus.find(menu_id);
-        if (it == m_menus.end()) {
-            ASSERT_NOT_REACHED();
-        }
-        auto& menu = *(*it).value;
-        menu.add_item(make<WSMenuItem>(WSMenuItem::Separator));
-        GUI_ServerMessage response;
-        response.type = GUI_ServerMessage::Type::DidAddMenuSeparator;
-        response.menu.menu_id = menu_id;
-        WSMessageLoop::the().post_message_to_client(request.client_id(), response);
-        break;
-    }
-    case WSMessage::APISetWindowTitleRequest: {
-        int window_id = static_cast<WSAPISetWindowTitleRequest&>(request).window_id();
-        auto it = m_windows_by_id.find(window_id);
-        if (it == m_windows_by_id.end()) {
-            ASSERT_NOT_REACHED();
-        }
-        auto& window = *(*it).value;
-        window.set_title(static_cast<WSAPISetWindowTitleRequest&>(request).title());
-        break;
-    }
-    case WSMessage::APIGetWindowTitleRequest: {
-        int window_id = static_cast<WSAPIGetWindowTitleRequest&>(request).window_id();
-        auto it = m_windows_by_id.find(window_id);
-        if (it == m_windows_by_id.end()) {
-            ASSERT_NOT_REACHED();
-        }
-        auto& window = *(*it).value;
-        GUI_ServerMessage response;
-        response.type = GUI_ServerMessage::Type::DidGetWindowTitle;
-        response.window_id = window.window_id();
-        ASSERT(window.title().length() < sizeof(response.text));
-        strcpy(response.text, window.title().characters());
-        response.text_length = window.title().length();
-        WSMessageLoop::the().post_message_to_client(request.client_id(), response);
-        break;
-    }
-    case WSMessage::APISetWindowRectRequest: {
-        int window_id = static_cast<WSAPISetWindowRectRequest&>(request).window_id();
-        auto it = m_windows_by_id.find(window_id);
-        if (it == m_windows_by_id.end()) {
-            ASSERT_NOT_REACHED();
-        }
-        auto& window = *(*it).value;
-        window.set_rect(static_cast<WSAPISetWindowRectRequest&>(request).rect());
-        break;
-    }
-    case WSMessage::APIGetWindowRectRequest: {
-        int window_id = static_cast<WSAPIGetWindowRectRequest&>(request).window_id();
-        auto it = m_windows_by_id.find(window_id);
-        if (it == m_windows_by_id.end()) {
-            ASSERT_NOT_REACHED();
-        }
-        auto& window = *(*it).value;
-        GUI_ServerMessage response;
-        response.type = GUI_ServerMessage::Type::DidGetWindowRect;
-        response.window_id = window.window_id();
-        response.window.rect = window.rect();
-        WSMessageLoop::the().post_message_to_client(request.client_id(), response);
-        break;
-    }
-    case WSMessage::APICreateWindowRequest: {
-        int window_id = m_next_window_id++;
-        auto window = make<WSWindow>(*WSMessageLoop::process_from_client_id(request.client_id()), window_id);
-        window->set_title(static_cast<WSAPICreateWindowRequest&>(request).title());
-        window->set_rect(static_cast<WSAPICreateWindowRequest&>(request).rect());
-        m_windows_by_id.set(window_id, move(window));
-        GUI_ServerMessage response;
-        response.type = GUI_ServerMessage::Type::DidCreateWindow;
-        response.window_id = window_id;
-        WSMessageLoop::the().post_message_to_client(request.client_id(), response);
-        break;
-    }
-    case WSMessage::APIDestroyWindowRequest: {
-        int window_id = static_cast<WSAPIGetWindowRectRequest&>(request).window_id();
-        auto it = m_windows_by_id.find(window_id);
-        if (it == m_windows_by_id.end()) {
-            ASSERT_NOT_REACHED();
-        }
-        auto& window = *(*it).value;
-        invalidate(window);
-        m_windows_by_id.remove(it);
-        break;
-    }
-    case WSMessage::APIInvalidateRectRequest: {
-        int window_id = static_cast<WSAPIInvalidateRectRequest&>(request).window_id();
-        auto it = m_windows_by_id.find(window_id);
-        if (it == m_windows_by_id.end()) {
-            ASSERT_NOT_REACHED();
-        }
-        GUI_ServerMessage response;
-        response.type = GUI_ServerMessage::Type::Paint;
-        response.window_id = window_id;
-        response.paint.rect = static_cast<WSAPIInvalidateRectRequest&>(request).rect();
-        WSMessageLoop::the().post_message_to_client(request.client_id(), response);
-        break;
-    }
-    case WSMessage::APIDidFinishPaintingNotification: {
-        int window_id = static_cast<WSAPIDidFinishPaintingNotification&>(request).window_id();
-        auto it = m_windows_by_id.find(window_id);
-        if (it == m_windows_by_id.end()) {
-            ASSERT_NOT_REACHED();
-        }
-        auto& window = *(*it).value;
-        invalidate(window, static_cast<WSAPIDidFinishPaintingNotification&>(request).rect());
-        break;
-    }
-    case WSMessage::APIGetWindowBackingStoreRequest: {
-        int window_id = static_cast<WSAPIGetWindowBackingStoreRequest&>(request).window_id();
-        auto it = m_windows_by_id.find(window_id);
-        if (it == m_windows_by_id.end()) {
-            ASSERT_NOT_REACHED();
-        }
-        auto& window = *(*it).value;
-        auto* backing_store = window.backing();
-
-        // FIXME: It shouldn't work this way!
-        backing_store->retain();
-
-        GUI_ServerMessage response;
-        response.type = GUI_ServerMessage::Type::DidGetWindowBackingStore;
-        response.window_id = window_id;
-        response.backing.backing_store_id = backing_store;
-        response.backing.bpp = sizeof(RGBA32);
-        response.backing.pitch = backing_store->pitch();
-        response.backing.size = backing_store->size();
-        response.backing.pixels = reinterpret_cast<RGBA32*>(backing_store->client_region()->laddr().as_ptr());
-        WSMessageLoop::the().post_message_to_client(request.client_id(), response);
-        break;
-    }
-    case WSMessage::APIReleaseWindowBackingStoreRequest: {
-        int backing_store_id = static_cast<WSAPIReleaseWindowBackingStoreRequest&>(request).backing_store_id();
-        // FIXME: It shouldn't work this way!
-        auto* backing_store = (GraphicsBitmap*)backing_store_id;
-        backing_store->release();
-        break;
-    }
-    default:
-        break;
-    }
 }
 
 void WSWindowManager::set_active_window(WSWindow* window)
@@ -1028,15 +754,10 @@ void WSWindowManager::set_active_window(WSWindow* window)
         WSMessageLoop::the().post_message(m_active_window.ptr(), make<WSMessage>(WSMessage::WindowActivated));
         invalidate(*m_active_window);
 
-        ASSERT(window->process());
-        auto it = m_app_menubars.find(window->process()->gui_client_id());
-        if (it != m_app_menubars.end()) {
-            auto* menubar = (*it).value;
-            if (menubar != m_current_menubar)
-                set_current_menubar(menubar);
-        } else {
-            set_current_menubar(nullptr);
-        }
+        int client_id = window->client_id();
+        auto* client = WSClientConnection::from_client_id(client_id);
+        ASSERT(client);
+        set_current_menubar(client->app_menubar());
     }
 }
 
@@ -1119,44 +840,27 @@ void WSWindowManager::flush(const Rect& a_rect)
 void WSWindowManager::close_menu(WSMenu& menu)
 {
     LOCKER(m_lock);
-    if (m_current_menu == &menu)
+    if (current_menu() == &menu)
         close_current_menu();
 }
 
+void WSWindowManager::close_menubar(WSMenuBar& menubar)
+{
+    LOCKER(m_lock);
+    if (current_menubar() == &menubar)
+        set_current_menubar(nullptr);
+}
+
 int WSWindowManager::active_client_id() const
 {
     if (m_active_window)
-        return m_active_window->process()->gui_client_id();
+        return m_active_window->client_id();
     return 0;
 }
 
-void WSWindowManager::destroy_all_menus(Process& process)
+void WSWindowManager::notify_client_changed_app_menubar(WSClientConnection& client)
 {
-    LOCKER(m_lock);
-    Vector<int> menu_ids;
-    bool should_close_current_menu = false;
-    for (auto& it : m_menus) {
-        if (it.value->process() == &process)
-            menu_ids.append(it.value->menu_id());
-        if (m_current_menu == it.value.ptr())
-            should_close_current_menu = true;
-    }
-    if (should_close_current_menu)
-        close_current_menu();
-    for (int menu_id : menu_ids)
-        m_menus.remove(menu_id);
-
-    Vector<int> menubar_ids;
-    bool should_close_current_menubar = false;
-    for (auto& it : m_menubars) {
-        if (it.value->process() == &process)
-            menubar_ids.append(it.value->menubar_id());
-        if (m_current_menubar == it.value.ptr())
-            should_close_current_menubar = true;
-    }
-    if (should_close_current_menubar)
-        set_current_menubar(nullptr);
-    for (int menubar_id : menubar_ids)
-        m_menubars.remove(menubar_id);
-    m_app_menubars.remove(process.gui_client_id());
+    if (active_client_id() == client.client_id())
+        set_current_menubar(client.app_menubar());
+    invalidate();
 }
diff --git a/WindowServer/WSWindowManager.h b/WindowServer/WSWindowManager.h
index 707f82dc85..d27a98b18e 100644
--- a/WindowServer/WSWindowManager.h
+++ b/WindowServer/WSWindowManager.h
@@ -18,6 +18,7 @@ class WSMenuBar;
 class WSMouseEvent;
 class WSClientWantsToPaintMessage;
 class WSWindow;
+class WSClientConnection;
 class CharacterBitmap;
 class GraphicsBitmap;
 
@@ -31,6 +32,7 @@ public:
 
     void notify_title_changed(WSWindow&);
     void notify_rect_changed(WSWindow&, const Rect& oldRect, const Rect& newRect);
+    void notify_client_changed_app_menubar(WSClientConnection&);
 
     WSWindow* active_window() { return m_active_window.ptr(); }
     int active_client_id() const;
@@ -42,9 +44,9 @@ public:
     void draw_menubar();
 
     Rect menubar_rect() const;
-    WSMenuBar* current_menubar() { return m_current_menubar; }
+    WSMenuBar* current_menubar() { return m_current_menubar.ptr(); }
     void set_current_menubar(WSMenuBar*);
-    WSMenu* current_menu() { return m_current_menu; }
+    WSMenu* current_menu() { return m_current_menu.ptr(); }
     void set_current_menu(WSMenu*);
 
     void invalidate(const WSWindow&);
@@ -57,6 +59,7 @@ public:
     const Font& font() const { return *m_font; }
 
     void close_menu(WSMenu&);
+    void close_menubar(WSMenuBar&);
     Color menu_selection_color() const { return m_menu_selection_color; }
     int menubar_menu_margin() const;
 
@@ -70,7 +73,7 @@ private:
 
     void process_mouse_event(WSMouseEvent&);
     void handle_menu_mouse_event(WSMenu&, WSMouseEvent&);
-    void handle_menubar_mouse_event(WSMenuBar&, WSMouseEvent&);
+    void handle_menubar_mouse_event(WSMouseEvent&);
     void handle_titlebar_mouse_event(WSWindow&, WSMouseEvent&);
     void handle_close_button_mouse_event(WSWindow&, WSMouseEvent&);
     void handle_client_request(WSAPIClientRequest&);
@@ -145,15 +148,8 @@ private:
     Lockable<bool> m_flash_flush;
     bool m_buffers_are_flipped { false };
 
-    int m_next_menubar_id { 100 };
-    int m_next_menu_id { 100 };
-    int m_next_window_id { 1982 };
-
     OwnPtr<WSMenu> m_system_menu;
     Color m_menu_selection_color;
-    WSMenuBar* m_current_menubar { nullptr };
-    WSMenu* m_current_menu { nullptr };
-    HashMap<int, OwnPtr<WSMenuBar>> m_menubars;
-    HashMap<int, OwnPtr<WSMenu>> m_menus;
-    HashMap<int, WSMenuBar*> m_app_menubars;
+    WeakPtr<WSMenuBar> m_current_menubar;
+    WeakPtr<WSMenu> m_current_menu;
 };