diff --git a/HMCL/src/main/java/org/jackhuang/hmcl/game/LauncherHelper.java b/HMCL/src/main/java/org/jackhuang/hmcl/game/LauncherHelper.java
index 2433bc526..d4931efef 100644
--- a/HMCL/src/main/java/org/jackhuang/hmcl/game/LauncherHelper.java
+++ b/HMCL/src/main/java/org/jackhuang/hmcl/game/LauncherHelper.java
@@ -20,11 +20,7 @@ package org.jackhuang.hmcl.game;
 import javafx.application.Platform;
 import javafx.stage.Stage;
 import org.jackhuang.hmcl.Launcher;
-import org.jackhuang.hmcl.auth.Account;
-import org.jackhuang.hmcl.auth.AuthInfo;
-import org.jackhuang.hmcl.auth.AuthenticationException;
-import org.jackhuang.hmcl.auth.CharacterDeletedException;
-import org.jackhuang.hmcl.auth.CredentialExpiredException;
+import org.jackhuang.hmcl.auth.*;
 import org.jackhuang.hmcl.auth.authlibinjector.AuthlibInjectorDownloadException;
 import org.jackhuang.hmcl.download.DefaultDependencyManager;
 import org.jackhuang.hmcl.download.MaintainTask;
@@ -51,11 +47,7 @@ import org.jackhuang.hmcl.ui.LogWindow;
 import org.jackhuang.hmcl.ui.construct.DialogCloseEvent;
 import org.jackhuang.hmcl.ui.construct.MessageDialogPane.MessageType;
 import org.jackhuang.hmcl.ui.construct.TaskExecutorDialogPane;
-import org.jackhuang.hmcl.util.Log4jLevel;
-import org.jackhuang.hmcl.util.Logging;
-import org.jackhuang.hmcl.util.Pair;
-import org.jackhuang.hmcl.util.StringUtils;
-import org.jackhuang.hmcl.util.function.ExceptionalSupplier;
+import org.jackhuang.hmcl.util.*;
 import org.jackhuang.hmcl.util.gson.UUIDTypeAdapter;
 import org.jackhuang.hmcl.util.io.ResponseCodeException;
 import org.jackhuang.hmcl.util.platform.CommandBuilder;
@@ -68,16 +60,9 @@ import java.io.File;
 import java.io.FileNotFoundException;
 import java.io.IOException;
 import java.net.URL;
-import java.util.Collections;
-import java.util.Comparator;
-import java.util.LinkedList;
-import java.util.Map;
-import java.util.Objects;
-import java.util.Optional;
-import java.util.Queue;
+import java.util.*;
 import java.util.concurrent.ConcurrentLinkedQueue;
 import java.util.concurrent.CountDownLatch;
-import java.util.concurrent.atomic.AtomicInteger;
 
 import static org.jackhuang.hmcl.setting.ConfigHolder.config;
 import static org.jackhuang.hmcl.util.Lang.mapOf;
@@ -102,9 +87,11 @@ public final class LauncherHelper {
         this.setting = profile.getVersionSetting(selectedVersion);
         this.launcherVisibility = setting.getLauncherVisibility();
         this.showLogs = setting.isShowLogs();
+        this.launchingStepsPane.setTitle(i18n("version.launch"));
     }
 
     private final TaskExecutorDialogPane launchingStepsPane = new TaskExecutorDialogPane(it -> {});
+    private CountDownLatch launchingLatch;
 
     public void setTestMode() {
         launcherVisibility = LauncherVisibility.KEEP;
@@ -140,15 +127,15 @@ public final class LauncherHelper {
         Version version = MaintainTask.maintain(repository, repository.getResolvedVersion(selectedVersion));
         Optional<String> gameVersion = GameVersion.minecraftVersion(repository.getVersionJar(version));
 
-        TaskExecutor executor = Task.runAsync(Schedulers.javafx(), () -> emitStatus(LoadingState.DEPENDENCIES))
-                .thenComposeAsync(() -> {
+        TaskExecutor executor = Task.runAsync(() -> {
+        })
+                .thenComposeAsync(() -> Task.composeAsync(() -> {
                     if (setting.isNotCheckGame())
                         return null;
                     else
                         return dependencyManager.checkGameCompletionAsync(version);
-                })
-                .thenRunAsync(Schedulers.javafx(), () -> emitStatus(LoadingState.MODS))
-                .thenComposeAsync(() -> {
+                }).withStage("launch.state.dependencies"))
+                .thenComposeAsync(() -> Task.composeAsync(null, () -> {
                     try {
                         ModpackConfiguration<?> configuration = ModpackHelper.readModpackConfiguration(repository.getModpackConfiguration(selectedVersion));
                         if ("Curse".equals(configuration.getType()))
@@ -160,9 +147,8 @@ public final class LauncherHelper {
                     } catch (IOException e) {
                         return null;
                     }
-                })
-                .thenRunAsync(Schedulers.javafx(), () -> emitStatus(LoadingState.LOGGING_IN))
-                .thenSupplyAsync(i18n("launch.state.logging_in"), () -> {
+                }).withStage("launch.state.modpack"))
+                .thenComposeAsync(() -> Task.supplyAsync((String) null, () -> {
                     try {
                         return account.logIn();
                     } catch (CredentialExpiredException e) {
@@ -172,31 +158,27 @@ public final class LauncherHelper {
                         LOG.warning("Authentication failed, try playing offline: " + e);
                         return account.playOffline().orElseThrow(() -> e);
                     }
-                })
-                .thenApplyAsync(Schedulers.javafx(), authInfo -> {
-                    emitStatus(LoadingState.LAUNCHING);
-                    return authInfo;
-                })
-                .thenApplyAsync(authInfo -> new HMCLGameLauncher(
-                        repository,
-                        version.getPatches().isEmpty() ? repository.getResolvedVersion(selectedVersion) : version,
-                        authInfo,
-                        setting.toLaunchOptions(profile.getGameDir(), !setting.isNotCheckJVM()),
-                        launcherVisibility == LauncherVisibility.CLOSE
-                                ? null // Unnecessary to start listening to game process output when close launcher immediately after game launched.
-                                : new HMCLProcessListener(authInfo, gameVersion.isPresent())
-                ))
-                .thenComposeAsync(launcher -> { // launcher is prev task's result
+                }).withStage("launch.state.logging_in"))
+                .thenComposeAsync(authInfo -> Task.supplyAsync((String) null, () -> {
+                    return new HMCLGameLauncher(
+                            repository,
+                            version.getPatches().isEmpty() ? repository.getResolvedVersion(selectedVersion) : version,
+                            authInfo,
+                            setting.toLaunchOptions(profile.getGameDir(), !setting.isNotCheckJVM()),
+                            launcherVisibility == LauncherVisibility.CLOSE
+                                    ? null // Unnecessary to start listening to game process output when close launcher immediately after game launched.
+                                    : new HMCLProcessListener(authInfo, gameVersion.isPresent())
+                    );
+                }).thenComposeAsync(launcher -> { // launcher is prev task's result
                     if (scriptFile == null) {
-                        return new LaunchTask<>(launcher::launch).setName(i18n("version.launch"));
+                        return Task.supplyAsync((String) null, launcher::launch);
                     } else {
-                        return new LaunchTask<ManagedProcess>(() -> {
+                        return Task.supplyAsync((String) null, () -> {
                             launcher.makeLaunchScript(scriptFile);
                             return null;
-                        }).setName(i18n("version.launch_script"));
+                        });
                     }
-                })
-                .thenAcceptAsync(process -> { // process is LaunchTask's result
+                }).thenAcceptAsync(process -> { // process is LaunchTask's result
                     if (scriptFile == null) {
                         PROCESSES.add(process);
                         if (launcherVisibility == LauncherVisibility.CLOSE)
@@ -212,19 +194,18 @@ public final class LauncherHelper {
                             Controllers.dialog(i18n("version.launch_script.success", scriptFile.getAbsolutePath()));
                         });
                     }
-                })
+                }).thenRunAsync(null, Schedulers.defaultScheduler(), () -> {
+                    launchingLatch = new CountDownLatch(1);
+                    launchingLatch.await();
+                }).withStage("launch.state.waiting_launching"))
                 .cancellableExecutor();
 
-        launchingStepsPane.setExecutor(executor, false);
+        launchingStepsPane.setExecutor(executor, Lang.immutableListOf(
+                "launch.state.dependencies",
+                "launch.state.modpack",
+                "launch.state.logging_in",
+                "launch.state.waiting_launching"), false);
         executor.addTaskListener(new TaskListener() {
-            final AtomicInteger finished = new AtomicInteger(0);
-
-            @Override
-            public void onFinished(Task<?> task) {
-                finished.incrementAndGet();
-                int runningTasks = executor.getRunningTasks();
-                Platform.runLater(() -> launchingStepsPane.setProgress(1.0 * finished.get() / runningTasks));
-            }
 
             @Override
             public void onStop(boolean success, TaskExecutor executor) {
@@ -432,15 +413,6 @@ public final class LauncherHelper {
             onAccept.run();
     }
 
-    public void emitStatus(LoadingState state) {
-        if (state == LoadingState.DONE) {
-            launchingStepsPane.fireEvent(new DialogCloseEvent());
-        }
-
-        launchingStepsPane.setTitle(state.getLocalizedMessage());
-        launchingStepsPane.setSubtitle((state.ordinal() + 1) + " / " + LoadingState.values().length);
-    }
-
     private void checkExit() {
         switch (launcherVisibility) {
             case HIDE_AND_REOPEN:
@@ -465,19 +437,6 @@ public final class LauncherHelper {
         }
     }
 
-    private static class LaunchTask<T> extends Task<T> {
-        private final ExceptionalSupplier<T, Exception> supplier;
-
-        public LaunchTask(ExceptionalSupplier<T, Exception> supplier) {
-            this.supplier = supplier;
-        }
-
-        @Override
-        public void execute() throws Exception {
-            setResult(supplier.get());
-        }
-    }
-
     /**
      * The managed process listener.
      * Guarantee that one [JavaProcess], one [HMCLProcessListener].
@@ -534,7 +493,7 @@ public final class LauncherHelper {
                         // these codes will be executed.
                         if (Controllers.getStage() != null) {
                             Controllers.getStage().hide();
-                            emitStatus(LoadingState.DONE);
+                            launchingLatch.countDown();
                         }
                     });
                     break;
@@ -543,7 +502,7 @@ public final class LauncherHelper {
                     break;
                 case KEEP:
                     Platform.runLater(() -> {
-                        emitStatus(LoadingState.DONE);
+                        launchingLatch.countDown();
                     });
                     break;
                 case HIDE:
@@ -552,7 +511,7 @@ public final class LauncherHelper {
                         // these codes will be executed.
                         if (Controllers.getStage() != null) {
                             Controllers.getStage().close();
-                            emitStatus(LoadingState.DONE);
+                            launchingLatch.countDown();
                         }
                     });
                     break;
diff --git a/HMCL/src/main/java/org/jackhuang/hmcl/ui/Controllers.java b/HMCL/src/main/java/org/jackhuang/hmcl/ui/Controllers.java
index 212705752..98cda500c 100644
--- a/HMCL/src/main/java/org/jackhuang/hmcl/ui/Controllers.java
+++ b/HMCL/src/main/java/org/jackhuang/hmcl/ui/Controllers.java
@@ -248,18 +248,13 @@ public final class Controllers {
         return pane;
     }
 
-    public static Region taskDialog(TaskExecutor executor, String title) {
-        return taskDialog(executor, title, "");
+    public static TaskExecutorDialogPane taskDialog(TaskExecutor executor, String title) {
+        return taskDialog(executor, title, null);
     }
 
-    public static Region taskDialog(TaskExecutor executor, String title, String subtitle) {
-        return taskDialog(executor, title, subtitle, null);
-    }
-
-    public static Region taskDialog(TaskExecutor executor, String title, String subtitle, Consumer<Region> onCancel) {
+    public static TaskExecutorDialogPane taskDialog(TaskExecutor executor, String title, Consumer<Region> onCancel) {
         TaskExecutorDialogPane pane = new TaskExecutorDialogPane(onCancel);
         pane.setTitle(title);
-        pane.setSubtitle(subtitle);
         pane.setExecutor(executor);
         dialog(pane);
         return pane;
diff --git a/HMCL/src/main/java/org/jackhuang/hmcl/ui/SVG.java b/HMCL/src/main/java/org/jackhuang/hmcl/ui/SVG.java
index a1f08286e..cfd9e679e 100644
--- a/HMCL/src/main/java/org/jackhuang/hmcl/ui/SVG.java
+++ b/HMCL/src/main/java/org/jackhuang/hmcl/ui/SVG.java
@@ -71,6 +71,10 @@ public final class SVG {
         return createSVGPath("M12,16A2,2 0 0,1 14,18A2,2 0 0,1 12,20A2,2 0 0,1 10,18A2,2 0 0,1 12,16M12,10A2,2 0 0,1 14,12A2,2 0 0,1 12,14A2,2 0 0,1 10,12A2,2 0 0,1 12,10M12,4A2,2 0 0,1 14,6A2,2 0 0,1 12,8A2,2 0 0,1 10,6A2,2 0 0,1 12,4Z", fill, width, height);
     }
 
+    public static Node dotsHorizontal(ObjectBinding<? extends Paint> fill, double width, double height) {
+        return createSVGPath("M16,12A2,2 0 0,1 18,10A2,2 0 0,1 20,12A2,2 0 0,1 18,14A2,2 0 0,1 16,12M10,12A2,2 0 0,1 12,10A2,2 0 0,1 14,12A2,2 0 0,1 12,14A2,2 0 0,1 10,12M4,12A2,2 0 0,1 6,10A2,2 0 0,1 8,12A2,2 0 0,1 6,14A2,2 0 0,1 4,12Z", fill, width, height);
+    }
+
     public static Node delete(ObjectBinding<? extends Paint> fill, double width, double height) {
         return createSVGPath("M19,4H15.5L14.5,3H9.5L8.5,4H5V6H19M6,19A2,2 0 0,0 8,21H16A2,2 0 0,0 18,19V7H6V19Z", fill, width, height);
     }
@@ -170,4 +174,8 @@ public final class SVG {
     public static Node check(ObjectBinding<? extends Paint> fill, double width, double height) {
         return createSVGPath("M21,7L9,19L3.5,13.5L4.91,12.09L9,16.17L19.59,5.59L21,7Z", fill, width, height);
     }
+
+    public static Node arrowRight(ObjectBinding<? extends Paint> fill, double width, double height) {
+        return createSVGPath("M4,11V13H16L10.5,18.5L11.92,19.92L19.84,12L11.92,4.08L10.5,5.5L16,11H4Z", fill, width, height);
+    }
 }
diff --git a/HMCL/src/main/java/org/jackhuang/hmcl/ui/construct/AdvancedListBox.java b/HMCL/src/main/java/org/jackhuang/hmcl/ui/construct/AdvancedListBox.java
index ca083c08e..d02f11fa4 100644
--- a/HMCL/src/main/java/org/jackhuang/hmcl/ui/construct/AdvancedListBox.java
+++ b/HMCL/src/main/java/org/jackhuang/hmcl/ui/construct/AdvancedListBox.java
@@ -53,22 +53,37 @@ public class AdvancedListBox extends ScrollPane {
         return this;
     }
 
-    public AdvancedListBox remove(Node child) {
-        if (child instanceof Pane)
-            container.getChildren().remove(child);
+    public AdvancedListBox add(int index, Node child) {
+        if (child instanceof Pane || child instanceof AdvancedListItem)
+            container.getChildren().add(index, child);
         else {
-            StackPane pane = null;
-            for (Node node : container.getChildren())
+            StackPane pane = new StackPane();
+            pane.getStyleClass().add("advanced-list-box-item");
+            pane.getChildren().setAll(child);
+            container.getChildren().add(index, pane);
+        }
+        return this;
+    }
+
+    public AdvancedListBox remove(Node child) {
+        container.getChildren().remove(indexOf(child));
+        return this;
+    }
+
+    public int indexOf(Node child) {
+        if (child instanceof Pane) {
+            return container.getChildren().indexOf(child);
+        } else {
+            for (int i = 0; i < container.getChildren().size(); ++i) {
+                Node node = container.getChildren().get(i);
                 if (node instanceof StackPane) {
                     ObservableList<Node> list = ((StackPane) node).getChildren();
                     if (list.size() == 1 && list.get(0) == child)
-                        pane = (StackPane) node;
+                        return i;
                 }
-            if (pane == null)
-                throw new Error();
-            container.getChildren().remove(pane);
+            }
+            return -1;
         }
-        return this;
     }
 
     public AdvancedListBox startCategory(String category) {
diff --git a/HMCL/src/main/java/org/jackhuang/hmcl/ui/construct/TaskExecutorDialogPane.java b/HMCL/src/main/java/org/jackhuang/hmcl/ui/construct/TaskExecutorDialogPane.java
index 2e5308ab5..6790eb11b 100644
--- a/HMCL/src/main/java/org/jackhuang/hmcl/ui/construct/TaskExecutorDialogPane.java
+++ b/HMCL/src/main/java/org/jackhuang/hmcl/ui/construct/TaskExecutorDialogPane.java
@@ -18,18 +18,19 @@
 package org.jackhuang.hmcl.ui.construct;
 
 import com.jfoenix.controls.JFXButton;
-import com.jfoenix.controls.JFXProgressBar;
 import javafx.application.Platform;
-import javafx.beans.binding.Bindings;
 import javafx.beans.property.StringProperty;
 import javafx.fxml.FXML;
 import javafx.scene.control.Label;
 import javafx.scene.layout.Region;
 import javafx.scene.layout.StackPane;
+import org.jackhuang.hmcl.task.FileDownloadTask;
 import org.jackhuang.hmcl.task.TaskExecutor;
 import org.jackhuang.hmcl.task.TaskListener;
 import org.jackhuang.hmcl.ui.FXUtils;
 
+import java.util.Collections;
+import java.util.List;
 import java.util.Optional;
 import java.util.function.Consumer;
 
@@ -38,14 +39,11 @@ import static org.jackhuang.hmcl.ui.FXUtils.runInFX;
 public class TaskExecutorDialogPane extends StackPane {
     private TaskExecutor executor;
     private Consumer<Region> onCancel;
+    private final Consumer<FileDownloadTask.SpeedEvent> speedEventHandler;
 
-    @FXML
-    private JFXProgressBar progressBar;
     @FXML
     private Label lblTitle;
     @FXML
-    private Label lblSubtitle;
-    @FXML
     private Label lblProgress;
     @FXML
     private JFXButton btnCancel;
@@ -62,10 +60,24 @@ public class TaskExecutorDialogPane extends StackPane {
             onCancel.accept(this);
         });
 
-        lblProgress.textProperty().bind(Bindings.createStringBinding(
-                () -> taskListPane.finishedTasksProperty().get() + "/" + taskListPane.totTasksProperty().get(),
-                taskListPane.finishedTasksProperty(), taskListPane.totTasksProperty()
-        ));
+        speedEventHandler = speedEvent -> {
+            String unit = "B/s";
+            double speed = speedEvent.getSpeed();
+            if (speed > 1024) {
+                speed /= 1024;
+                unit = "KB/s";
+            }
+            if (speed > 1024) {
+                speed /= 1024;
+                unit = "MB/s";
+            }
+            double finalSpeed = speed;
+            String finalUnit = unit;
+            Platform.runLater(() -> {
+                lblProgress.setText(String.format("%.1f", finalSpeed) + " " + finalUnit);
+            });
+        };
+        FileDownloadTask.speedEvent.channel(FileDownloadTask.SpeedEvent.class).registerWeak(speedEventHandler);
     }
 
     public void setExecutor(TaskExecutor executor) {
@@ -73,10 +85,18 @@ public class TaskExecutorDialogPane extends StackPane {
     }
 
     public void setExecutor(TaskExecutor executor, boolean autoClose) {
+        setExecutor(executor, Collections.emptyList(), autoClose);
+    }
+
+    public void setExecutor(TaskExecutor executor, List<String> stages) {
+        setExecutor(executor, stages, true);
+    }
+
+    public void setExecutor(TaskExecutor executor, List<String> stages, boolean autoClose) {
         this.executor = executor;
 
         if (executor != null) {
-            taskListPane.setExecutor(executor);
+            taskListPane.setExecutor(executor, stages);
 
             if (autoClose)
                 executor.addTaskListener(new TaskListener() {
@@ -100,25 +120,6 @@ public class TaskExecutorDialogPane extends StackPane {
         lblTitle.setText(currentState);
     }
 
-    public StringProperty subtitleProperty() {
-        return lblSubtitle.textProperty();
-    }
-
-    public String getSubtitle() {
-        return lblSubtitle.getText();
-    }
-
-    public void setSubtitle(String subtitle) {
-        lblSubtitle.setText(subtitle);
-    }
-
-    public void setProgress(double progress) {
-        if (progress == Double.MAX_VALUE)
-            progressBar.setVisible(false);
-        else
-            progressBar.setProgress(progress);
-    }
-
     public void setCancel(Consumer<Region> onCancel) {
         this.onCancel = onCancel;
 
diff --git a/HMCL/src/main/java/org/jackhuang/hmcl/ui/construct/TaskListPane.java b/HMCL/src/main/java/org/jackhuang/hmcl/ui/construct/TaskListPane.java
index 3ddba4b56..372e4bc57 100644
--- a/HMCL/src/main/java/org/jackhuang/hmcl/ui/construct/TaskListPane.java
+++ b/HMCL/src/main/java/org/jackhuang/hmcl/ui/construct/TaskListPane.java
@@ -21,6 +21,8 @@ import com.jfoenix.controls.JFXProgressBar;
 import javafx.application.Platform;
 import javafx.beans.property.ReadOnlyIntegerProperty;
 import javafx.beans.property.ReadOnlyIntegerWrapper;
+import javafx.geometry.Insets;
+import javafx.geometry.Pos;
 import javafx.scene.control.Label;
 import javafx.scene.layout.BorderPane;
 import javafx.scene.layout.StackPane;
@@ -37,20 +39,22 @@ import org.jackhuang.hmcl.mod.ModpackUpdateTask;
 import org.jackhuang.hmcl.mod.curse.CurseCompletionTask;
 import org.jackhuang.hmcl.mod.curse.CurseInstallTask;
 import org.jackhuang.hmcl.mod.multimc.MultiMCModpackInstallTask;
+import org.jackhuang.hmcl.setting.Theme;
 import org.jackhuang.hmcl.task.Task;
 import org.jackhuang.hmcl.task.TaskExecutor;
 import org.jackhuang.hmcl.task.TaskListener;
+import org.jackhuang.hmcl.ui.FXUtils;
+import org.jackhuang.hmcl.ui.SVG;
 
-import java.util.HashMap;
-import java.util.Map;
+import java.util.*;
+import java.util.stream.Collectors;
 
 import static org.jackhuang.hmcl.util.i18n.I18n.i18n;
 
 public final class TaskListPane extends StackPane {
     private final AdvancedListBox listBox = new AdvancedListBox();
     private final Map<Task<?>, ProgressListNode> nodes = new HashMap<>();
-    private final ReadOnlyIntegerWrapper finishedTasks = new ReadOnlyIntegerWrapper();
-    private final ReadOnlyIntegerWrapper totTasks = new ReadOnlyIntegerWrapper();
+    private final List<StageNode> stageNodes = new ArrayList<>();
 
     public TaskListPane() {
         listBox.setSpacing(0);
@@ -58,33 +62,35 @@ public final class TaskListPane extends StackPane {
         getChildren().setAll(listBox);
     }
 
-    public ReadOnlyIntegerProperty finishedTasksProperty() {
-        return finishedTasks.getReadOnlyProperty();
-    }
-
-    public ReadOnlyIntegerProperty totTasksProperty() {
-        return totTasks.getReadOnlyProperty();
-    }
-
     public void setExecutor(TaskExecutor executor) {
+        setExecutor(executor, Collections.emptyList());
+    }
+
+    public void setExecutor(TaskExecutor executor, List<String> stages) {
+
         executor.addTaskListener(new TaskListener() {
             @Override
             public void onStart() {
                 Platform.runLater(() -> {
+                    stageNodes.clear();
                     listBox.clear();
-                    finishedTasks.set(0);
-                    totTasks.set(0);
+                    stageNodes.addAll(stages.stream().map(StageNode::new).collect(Collectors.toList()));
+                    stageNodes.forEach(listBox::add);
                 });
             }
 
             @Override
             public void onReady(Task<?> task) {
-                Platform.runLater(() -> totTasks.set(totTasks.getValue() + 1));
+                if (task instanceof Task.StageTask) {
+                    Platform.runLater(() -> {
+                        stageNodes.stream().filter(x -> x.stage.equals(task.getStage())).findAny().ifPresent(StageNode::begin);
+                    });
+                }
             }
 
             @Override
             public void onRunning(Task<?> task) {
-                if (!task.getSignificance().shouldShow())
+                if (!task.getSignificance().shouldShow() || task.getName() == null)
                     return;
 
                 if (task instanceof GameAssetDownloadTask) {
@@ -117,34 +123,77 @@ public final class TaskListPane extends StackPane {
 
                 ProgressListNode node = new ProgressListNode(task);
                 nodes.put(task, node);
-                Platform.runLater(() -> listBox.add(node));
+                Platform.runLater(() -> {
+                    StageNode stageNode = stageNodes.stream().filter(x -> x.stage.equals(task.getStage())).findAny().orElse(null);
+                    listBox.add(listBox.indexOf(stageNode) + 1, node);
+                });
             }
 
             @Override
             public void onFinished(Task<?> task) {
+                if (task instanceof Task.StageTask) {
+                    Platform.runLater(() -> {
+                        stageNodes.stream().filter(x -> x.stage.equals(task.getStage())).findAny().ifPresent(StageNode::succeed);
+                    });
+                }
+
                 ProgressListNode node = nodes.remove(task);
                 if (node == null)
                     return;
                 node.unbind();
                 Platform.runLater(() -> {
                     listBox.remove(node);
-                    finishedTasks.set(finishedTasks.getValue() + 1);
                 });
             }
 
             @Override
             public void onFailed(Task<?> task, Throwable throwable) {
+                if (task instanceof Task.StageTask) {
+                    Platform.runLater(() -> {
+                        stageNodes.stream().filter(x -> x.stage.equals(task.getStage())).findAny().ifPresent(StageNode::fail);
+                    });
+                }
                 ProgressListNode node = nodes.remove(task);
                 if (node == null)
                     return;
                 Platform.runLater(() -> {
                     node.setThrowable(throwable);
-                    finishedTasks.set(finishedTasks.getValue() + 1);
                 });
             }
         });
     }
 
+    private static class StageNode extends BorderPane {
+        private final String stage;
+        private final Label title = new Label();
+        private boolean started = false;
+
+        public StageNode(String stage) {
+            this.stage = stage;
+
+            title.setText(i18n(stage));
+            BorderPane.setAlignment(title, Pos.CENTER_LEFT);
+            BorderPane.setMargin(title, new Insets(0, 0, 0, 8));
+            setPadding(new Insets(0, 0, 8, 4));
+            setCenter(title);
+            setLeft(SVG.dotsHorizontal(Theme.blackFillBinding(), 14, 14));
+        }
+
+        public void begin() {
+            if (started) return;
+            started = true;
+            setLeft(FXUtils.limitingSize(SVG.arrowRight(Theme.blackFillBinding(), 14, 14), 14, 14));
+        }
+
+        public void fail() {
+            setLeft(FXUtils.limitingSize(SVG.close(Theme.blackFillBinding(), 14, 14), 14, 14));
+        }
+
+        public void succeed() {
+            setLeft(FXUtils.limitingSize(SVG.check(Theme.blackFillBinding(), 14, 14), 14, 14));
+        }
+    }
+
     private static class ProgressListNode extends BorderPane {
         private final JFXProgressBar bar = new JFXProgressBar();
         private final Label title = new Label();
diff --git a/HMCL/src/main/java/org/jackhuang/hmcl/ui/wizard/TaskExecutorDialogWizardDisplayer.java b/HMCL/src/main/java/org/jackhuang/hmcl/ui/wizard/TaskExecutorDialogWizardDisplayer.java
index 53ddab7a8..32c42dd69 100644
--- a/HMCL/src/main/java/org/jackhuang/hmcl/ui/wizard/TaskExecutorDialogWizardDisplayer.java
+++ b/HMCL/src/main/java/org/jackhuang/hmcl/ui/wizard/TaskExecutorDialogWizardDisplayer.java
@@ -42,7 +42,6 @@ public interface TaskExecutorDialogWizardDisplayer extends AbstractWizardDisplay
         });
 
         pane.setTitle(i18n("message.doing"));
-        pane.setProgress(Double.MAX_VALUE);
         if (settings.containsKey("title")) {
             Object title = settings.get("title");
             if (title instanceof StringProperty)
@@ -51,14 +50,6 @@ public interface TaskExecutorDialogWizardDisplayer extends AbstractWizardDisplay
                 pane.setTitle((String) title);
         }
 
-        if (settings.containsKey("subtitle")) {
-            Object subtitle = settings.get("subtitle");
-            if (subtitle instanceof StringProperty)
-                pane.subtitleProperty().bind((StringProperty) subtitle);
-            else if (subtitle instanceof String)
-                pane.setSubtitle((String) subtitle);
-        }
-
         runInFX(() -> {
             TaskExecutor executor = task.cancellableExecutor(new TaskListener() {
                 @Override
diff --git a/HMCL/src/main/resources/assets/fxml/task-dialog.fxml b/HMCL/src/main/resources/assets/fxml/task-dialog.fxml
index 8dda27af9..4f1d67158 100644
--- a/HMCL/src/main/resources/assets/fxml/task-dialog.fxml
+++ b/HMCL/src/main/resources/assets/fxml/task-dialog.fxml
@@ -1,7 +1,6 @@
 <?xml version="1.0" encoding="UTF-8"?>
 
 <?import com.jfoenix.controls.JFXButton?>
-<?import com.jfoenix.controls.JFXProgressBar?>
 <?import javafx.scene.control.Label?>
 <?import javafx.scene.control.ScrollPane?>
 <?import javafx.scene.layout.*?>
@@ -11,13 +10,9 @@
          xmlns:fx="http://javafx.com/fxml"
          type="StackPane" FXUtils.limitWidth="500" FXUtils.limitHeight="300">
     <BorderPane>
-        <top>
-            <JFXProgressBar fx:id="progressBar" StackPane.alignment="TOP_CENTER" />
-        </top>
         <center>
-            <VBox alignment="TOP_CENTER" style="-fx-padding: 16px;">
-                <Label fx:id="lblTitle" style="-fx-font-size: 20px;" />
-                <Label fx:id="lblSubtitle" style="-fx-font-size: 14px;" />
+            <VBox style="-fx-padding: 16px;">
+                <Label fx:id="lblTitle" style="-fx-font-size: 14px; -fx-font-weight: BOLD;" />
 
                 <ScrollPane fitToHeight="true" fitToWidth="true" VBox.vgrow="ALWAYS">
                     <TaskListPane fx:id="taskListPane" />
diff --git a/HMCL/src/main/resources/assets/lang/I18N_zh.properties b/HMCL/src/main/resources/assets/lang/I18N_zh.properties
index 1b71368ff..ddd5d232f 100644
--- a/HMCL/src/main/resources/assets/lang/I18N_zh.properties
+++ b/HMCL/src/main/resources/assets/lang/I18N_zh.properties
@@ -179,10 +179,10 @@ launch.failed.decompressing_natives=無法解壓縮遊戲資源庫。
 launch.failed.download_library=無法下載遊戲相依元件 %s。
 launch.failed.executable_permission=無法為啟動檔案新增執行權限。
 launch.failed.exited_abnormally=遊戲非正常退出，請查看記錄檔案，或聯絡他人尋求幫助。
-launch.state.dependencies=正在處理遊戲相依元件
+launch.state.dependencies=處理遊戲相依元件
 launch.state.done=啟動完成
-launch.state.logging_in=登入中
-launch.state.modpack=正在下載必要檔案
+launch.state.logging_in=登入
+launch.state.modpack=下載必要檔案
 launch.state.waiting_launching=等待遊戲啟動
 launch.wrong_javadir=Java 路徑錯誤，將自動重設為預設 Java 路徑。
 
diff --git a/HMCL/src/main/resources/assets/lang/I18N_zh_CN.properties b/HMCL/src/main/resources/assets/lang/I18N_zh_CN.properties
index a27ec918a..0ff6ec304 100644
--- a/HMCL/src/main/resources/assets/lang/I18N_zh_CN.properties
+++ b/HMCL/src/main/resources/assets/lang/I18N_zh_CN.properties
@@ -180,10 +180,10 @@ launch.failed.decompressing_natives=未能解压游戏本地库。
 launch.failed.download_library=未能下载游戏依赖 %s.
 launch.failed.executable_permission=未能为启动文件添加执行权限。
 launch.failed.exited_abnormally=游戏非正常退出，请查看日志文件，或联系他人寻求帮助。
-launch.state.dependencies=正在处理游戏依赖
+launch.state.dependencies=处理游戏依赖
 launch.state.done=启动完成
-launch.state.logging_in=登录中
-launch.state.modpack=正在下载必要文件
+launch.state.logging_in=登录
+launch.state.modpack=下载必要文件
 launch.state.waiting_launching=等待游戏启动
 launch.wrong_javadir=错误的 Java 路径，将自动重置为默认 Java 路径。
 
diff --git a/HMCLCore/src/main/java/org/jackhuang/hmcl/task/AsyncTaskExecutor.java b/HMCLCore/src/main/java/org/jackhuang/hmcl/task/AsyncTaskExecutor.java
index 6ccee38ca..6cadd3d85 100644
--- a/HMCLCore/src/main/java/org/jackhuang/hmcl/task/AsyncTaskExecutor.java
+++ b/HMCLCore/src/main/java/org/jackhuang/hmcl/task/AsyncTaskExecutor.java
@@ -24,7 +24,10 @@ import org.jackhuang.hmcl.util.function.ExceptionalRunnable;
 
 import java.util.Collection;
 import java.util.Collections;
-import java.util.concurrent.*;
+import java.util.concurrent.CancellationException;
+import java.util.concurrent.CompletableFuture;
+import java.util.concurrent.CompletionException;
+import java.util.concurrent.ExecutionException;
 import java.util.logging.Level;
 
 /**
@@ -42,7 +45,7 @@ public final class AsyncTaskExecutor extends TaskExecutor {
     @Override
     public TaskExecutor start() {
         taskListeners.forEach(TaskListener::onStart);
-        future = executeTasks(Collections.singleton(firstTask))
+        future = executeTasks(null, Collections.singleton(firstTask))
                 .thenApplyAsync(exception -> {
                     boolean success = exception == null;
 
@@ -95,7 +98,7 @@ public final class AsyncTaskExecutor extends TaskExecutor {
         future.cancel(true);
     }
 
-    private CompletableFuture<Exception> executeTasks(Collection<Task<?>> tasks) {
+    private CompletableFuture<Exception> executeTasks(Task<?> parentTask, Collection<Task<?>> tasks) {
         if (tasks == null || tasks.isEmpty())
             return CompletableFuture.completedFuture(null);
 
@@ -105,7 +108,7 @@ public final class AsyncTaskExecutor extends TaskExecutor {
 
                     return CompletableFuture.allOf(tasks.stream()
                             .map(task -> CompletableFuture.completedFuture(null)
-                                    .thenComposeAsync(unused2 -> executeTask(task))
+                                    .thenComposeAsync(unused2 -> executeTask(parentTask, task))
                             ).toArray(CompletableFuture<?>[]::new));
                 })
                 .thenApplyAsync(unused -> (Exception) null)
@@ -120,11 +123,13 @@ public final class AsyncTaskExecutor extends TaskExecutor {
                 });
     }
 
-    private CompletableFuture<?> executeTask(Task<?> task) {
+    private CompletableFuture<?> executeTask(Task<?> parentTask, Task<?> task) {
         return CompletableFuture.completedFuture(null)
                 .thenComposeAsync(unused -> {
                     task.setCancelled(this::isCancelled);
                     task.setState(Task.TaskState.READY);
+                    if (parentTask != null && task.getStage() == null)
+                        task.setStage(parentTask.getStage());
 
                     if (task.getSignificance().shouldLog())
                         Logging.LOG.log(Level.FINE, "Executing task: " + task.getName());
@@ -137,7 +142,7 @@ public final class AsyncTaskExecutor extends TaskExecutor {
                         return CompletableFuture.completedFuture(null);
                     }
                 })
-                .thenComposeAsync(unused -> executeTasks(task.getDependents()))
+                .thenComposeAsync(unused -> executeTasks(task, task.getDependents()))
                 .thenComposeAsync(dependentsException -> {
                     boolean isDependentsSucceeded = dependentsException == null;
 
@@ -158,7 +163,7 @@ public final class AsyncTaskExecutor extends TaskExecutor {
                         rethrow(throwable);
                     });
                 })
-                .thenComposeAsync(unused -> executeTasks(task.getDependencies()))
+                .thenComposeAsync(unused -> executeTasks(task, task.getDependencies()))
                 .thenComposeAsync(dependenciesException -> {
                     boolean isDependenciesSucceeded = dependenciesException == null;
 
diff --git a/HMCLCore/src/main/java/org/jackhuang/hmcl/task/CancellableTaskExecutor.java b/HMCLCore/src/main/java/org/jackhuang/hmcl/task/CancellableTaskExecutor.java
index 835083c01..d362143a0 100644
--- a/HMCLCore/src/main/java/org/jackhuang/hmcl/task/CancellableTaskExecutor.java
+++ b/HMCLCore/src/main/java/org/jackhuang/hmcl/task/CancellableTaskExecutor.java
@@ -23,14 +23,7 @@ import org.jackhuang.hmcl.util.function.ExceptionalRunnable;
 import java.util.Collection;
 import java.util.Collections;
 import java.util.Objects;
-import java.util.concurrent.CancellationException;
-import java.util.concurrent.CompletionException;
-import java.util.concurrent.ConcurrentLinkedQueue;
-import java.util.concurrent.CountDownLatch;
-import java.util.concurrent.ExecutionException;
-import java.util.concurrent.Executor;
-import java.util.concurrent.Future;
-import java.util.concurrent.RejectedExecutionException;
+import java.util.concurrent.*;
 import java.util.concurrent.atomic.AtomicBoolean;
 import java.util.logging.Level;
 
@@ -47,7 +40,7 @@ public class CancellableTaskExecutor extends TaskExecutor {
     public TaskExecutor start() {
         taskListeners.forEach(TaskListener::onStart);
         workerQueue.add(Schedulers.schedule(scheduler, wrap(() -> {
-            boolean flag = executeTasks(Collections.singleton(firstTask));
+            boolean flag = executeTasks(null, Collections.singleton(firstTask));
             taskListeners.forEach(it -> it.onStop(flag, this));
         })));
         return this;
@@ -58,7 +51,7 @@ public class CancellableTaskExecutor extends TaskExecutor {
         taskListeners.forEach(TaskListener::onStart);
         AtomicBoolean flag = new AtomicBoolean(true);
         Future<?> future = Schedulers.schedule(scheduler, wrap(() -> {
-            flag.set(executeTasks(Collections.singleton(firstTask)));
+            flag.set(executeTasks(null, Collections.singleton(firstTask)));
             taskListeners.forEach(it -> it.onStop(flag.get(), this));
         }));
         workerQueue.add(future);
@@ -82,7 +75,7 @@ public class CancellableTaskExecutor extends TaskExecutor {
         }
     }
 
-    private boolean executeTasks(Collection<? extends Task<?>> tasks) throws InterruptedException {
+    private boolean executeTasks(Task<?> parentTask, Collection<? extends Task<?>> tasks) throws InterruptedException {
         if (tasks.isEmpty())
             return true;
 
@@ -92,7 +85,7 @@ public class CancellableTaskExecutor extends TaskExecutor {
         for (Task<?> task : tasks) {
             if (cancelled.get())
                 return false;
-            Invoker invoker = new Invoker(task, latch, success);
+            Invoker invoker = new Invoker(parentTask, task, latch, success);
             try {
                 Future<?> future = Schedulers.schedule(scheduler, invoker);
                 workerQueue.add(future);
@@ -112,7 +105,7 @@ public class CancellableTaskExecutor extends TaskExecutor {
         return success.get() && !cancelled.get();
     }
 
-    private boolean executeTask(Task<?> task) {
+    private boolean executeTask(Task<?> parentTask, Task<?> task) {
         task.setCancelled(this::isCancelled);
 
         if (cancelled.get()) {
@@ -122,6 +115,8 @@ public class CancellableTaskExecutor extends TaskExecutor {
         }
 
         task.setState(Task.TaskState.READY);
+        if (parentTask != null && task.getStage() == null)
+            task.setStage(parentTask.getStage());
 
         if (task.getSignificance().shouldLog())
             Logging.LOG.log(Level.FINE, "Executing task: " + task.getName());
@@ -140,8 +135,12 @@ public class CancellableTaskExecutor extends TaskExecutor {
             }
 
             Collection<? extends Task<?>> dependents = task.getDependents();
-            boolean doDependentsSucceeded = executeTasks(dependents);
-            Exception dependentsException = dependents.stream().map(Task::getException).filter(Objects::nonNull).findAny().orElse(null);
+            boolean doDependentsSucceeded = executeTasks(task, dependents);
+            Exception dependentsException = dependents.stream().map(Task::getException)
+                    .filter(Objects::nonNull)
+                    .filter(x -> !(x instanceof CancellationException))
+                    .filter(x -> !(x instanceof InterruptedException))
+                    .findAny().orElse(null);
             if (!doDependentsSucceeded && task.isRelyingOnDependents() || cancelled.get()) {
                 task.setException(dependentsException);
                 throw new CancellationException();
@@ -163,8 +162,12 @@ public class CancellableTaskExecutor extends TaskExecutor {
             }
 
             Collection<? extends Task<?>> dependencies = task.getDependencies();
-            boolean doDependenciesSucceeded = executeTasks(dependencies);
-            Exception dependenciesException = dependencies.stream().map(Task::getException).filter(Objects::nonNull).findAny().orElse(null);
+            boolean doDependenciesSucceeded = executeTasks(task, dependencies);
+            Exception dependenciesException = dependencies.stream().map(Task::getException)
+                    .filter(Objects::nonNull)
+                    .filter(x -> !(x instanceof CancellationException))
+                    .filter(x -> !(x instanceof InterruptedException))
+                    .findAny().orElse(null);
 
             if (doDependenciesSucceeded)
                 task.setDependenciesSucceeded();
@@ -250,11 +253,13 @@ public class CancellableTaskExecutor extends TaskExecutor {
 
     private class Invoker implements Runnable {
 
+        private final Task<?> parentTask;
         private final Task<?> task;
         private final CountDownLatch latch;
         private final AtomicBoolean success;
 
-        public Invoker(Task<?> task, CountDownLatch latch, AtomicBoolean success) {
+        public Invoker(Task<?> parentTask, Task<?> task, CountDownLatch latch, AtomicBoolean success) {
+            this.parentTask = parentTask;
             this.task = task;
             this.latch = latch;
             this.success = success;
@@ -264,7 +269,7 @@ public class CancellableTaskExecutor extends TaskExecutor {
         public void run() {
             try {
                 Thread.currentThread().setName(task.getName());
-                if (!executeTask(task))
+                if (!executeTask(parentTask, task))
                     success.set(false);
             } finally {
                 latch.countDown();
diff --git a/HMCLCore/src/main/java/org/jackhuang/hmcl/task/FileDownloadTask.java b/HMCLCore/src/main/java/org/jackhuang/hmcl/task/FileDownloadTask.java
index f1ee79799..76fcba7ac 100644
--- a/HMCLCore/src/main/java/org/jackhuang/hmcl/task/FileDownloadTask.java
+++ b/HMCLCore/src/main/java/org/jackhuang/hmcl/task/FileDownloadTask.java
@@ -17,13 +17,11 @@
  */
 package org.jackhuang.hmcl.task;
 
+import org.jackhuang.hmcl.event.Event;
+import org.jackhuang.hmcl.event.EventBus;
 import org.jackhuang.hmcl.util.CacheRepository;
 import org.jackhuang.hmcl.util.Logging;
-import org.jackhuang.hmcl.util.io.ChecksumMismatchException;
-import org.jackhuang.hmcl.util.io.FileUtils;
-import org.jackhuang.hmcl.util.io.IOUtils;
-import org.jackhuang.hmcl.util.io.NetworkUtils;
-import org.jackhuang.hmcl.util.io.ResponseCodeException;
+import org.jackhuang.hmcl.util.io.*;
 
 import java.io.File;
 import java.io.IOException;
@@ -35,10 +33,8 @@ import java.net.URL;
 import java.nio.file.Files;
 import java.nio.file.Path;
 import java.security.MessageDigest;
-import java.util.ArrayList;
-import java.util.Collections;
-import java.util.List;
-import java.util.Optional;
+import java.util.*;
+import java.util.concurrent.atomic.AtomicInteger;
 import java.util.logging.Level;
 
 import static java.util.Objects.requireNonNull;
@@ -279,7 +275,7 @@ public class FileDownloadTask extends Task<Void> {
                     updateProgress(downloaded, contentLength);
                     long now = System.currentTimeMillis();
                     if (now - lastTime >= 1000) {
-                        updateMessage((downloaded - lastDownloaded) / 1024 + "KB/s");
+                        updateDownloadSpeed(downloaded - lastDownloaded);
                         lastDownloaded = downloaded;
                         lastTime = now;
                     }
@@ -337,4 +333,39 @@ public class FileDownloadTask extends Task<Void> {
             throw new DownloadException(urls.get(0), exception);
     }
 
+    private static final Timer timer = new Timer("DownloadSpeedRecorder", true);
+    private static final AtomicInteger downloadSpeed = new AtomicInteger(0);
+    public static final EventBus speedEvent = new EventBus();
+
+    static {
+        timer.schedule(new TimerTask() {
+            @Override
+            public void run() {
+                speedEvent.fireEvent(new SpeedEvent(speedEvent, downloadSpeed.getAndSet(0)));
+            }
+        }, 0, 1000);
+    }
+
+    private static void updateDownloadSpeed(int speed) {
+        downloadSpeed.addAndGet(speed);
+    }
+
+    public static class SpeedEvent extends Event {
+        private final int speed;
+
+        public SpeedEvent(Object source, int speed) {
+            super(source);
+
+            this.speed = speed;
+        }
+
+        /**
+         * Download speed in byte/sec.
+         * @return
+         */
+        public int getSpeed() {
+            return speed;
+        }
+    }
+
 }
diff --git a/HMCLCore/src/main/java/org/jackhuang/hmcl/task/Task.java b/HMCLCore/src/main/java/org/jackhuang/hmcl/task/Task.java
index ad9e5e8d7..338427dcc 100644
--- a/HMCLCore/src/main/java/org/jackhuang/hmcl/task/Task.java
+++ b/HMCLCore/src/main/java/org/jackhuang/hmcl/task/Task.java
@@ -79,6 +79,25 @@ public abstract class Task<T> {
         return cancelled != null ? cancelled.get() : false;
     }
 
+    // stage
+    private String stage = null;
+
+    /**
+     * Stage of task implies the goal of this task, for grouping tasks.
+     * Stage will inherit from the parent task.
+     */
+    public String getStage() {
+        return stage;
+    }
+
+    /**
+     * You must initialize stage in preExecute.
+     * @param stage the stage
+     */
+    public void setStage(String stage) {
+        this.stage = stage;
+    }
+
     // state
     private TaskState state = TaskState.READY;
 
@@ -344,18 +363,18 @@ public abstract class Task<T> {
     }
 
     public final TaskExecutor cancellableExecutor() {
-        return new CancellableTaskExecutor(this);
+        return new AsyncTaskExecutor(this);
     }
 
     public final TaskExecutor cancellableExecutor(boolean start) {
-        TaskExecutor executor = new CancellableTaskExecutor(this);
+        TaskExecutor executor = new AsyncTaskExecutor(this);
         if (start)
             executor.start();
         return executor;
     }
 
     public final TaskExecutor cancellableExecutor(TaskListener taskListener) {
-        TaskExecutor executor = new CancellableTaskExecutor(this);
+        TaskExecutor executor = new AsyncTaskExecutor(this);
         executor.addTaskListener(taskListener);
         return executor;
     }
@@ -743,6 +762,12 @@ public abstract class Task<T> {
         return whenComplete(executor, () -> success.accept(getResult()), failure);
     }
 
+    public Task<T> withStage(String stage) {
+        StageTask<T> task = new StageTask<>(this);
+        task.setStage(stage);
+        return task;
+    }
+
     public static Task<Void> runAsync(ExceptionalRunnable<?> closure) {
         return runAsync(Schedulers.defaultScheduler(), closure);
     }
@@ -760,6 +785,10 @@ public abstract class Task<T> {
     }
 
     public static <T> Task<T> composeAsync(ExceptionalSupplier<Task<T>, ?> fn) {
+        return composeAsync(getCaller(), fn);
+    }
+
+    public static <T> Task<T> composeAsync(String name, ExceptionalSupplier<Task<T>, ?> fn) {
         return new Task<T>() {
             Task<T> then;
 
@@ -774,7 +803,7 @@ public abstract class Task<T> {
             public Collection<Task<?>> getDependencies() {
                 return then == null ? Collections.emptySet() : Collections.singleton(then);
             }
-        };
+        }.setName(name);
     }
 
     public static <V> Task<V> supplyAsync(Callable<V> callable) {
@@ -960,4 +989,21 @@ public abstract class Task<T> {
             return relyingOnDependents;
         }
     }
+
+    public static class StageTask<T> extends Task<T> {
+        private final Task<T> task;
+        StageTask(Task<T> task) {
+            this.task = task;
+        }
+
+        @Override
+        public Collection<Task<?>> getDependents() {
+            return Collections.singleton(task);
+        }
+
+        @Override
+        public void execute() throws Exception {
+            setResult(task.getResult());
+        }
+    }
 }