diff --git a/Installer/AppDelegate.swift b/Installer/AppDelegate.swift
index f089c231..918cd0b1 100644
--- a/Installer/AppDelegate.swift
+++ b/Installer/AppDelegate.swift
@@ -8,7 +8,7 @@
 // marks, or product names of Contributor, except as required to fulfill notice
 // requirements defined in MIT License.
 
-import Cocoa
+import AppKit
 import IMKUtils
 import InputMethodKit
 import SwiftExtension
@@ -111,7 +111,7 @@ class AppDelegate: NSWindowController, NSApplicationDelegate {
 
     window.center()
     window.orderFront(self)
-    NSApp.activate(ignoringOtherApps: true)
+    NSApp.popup()
   }
 
   @IBAction func agreeAndInstallAction(_: AnyObject) {
@@ -179,3 +179,21 @@ class AppDelegate: NSWindowController, NSApplicationDelegate {
     return output
   }
 }
+
+// MARK: - NSApp Activation Helper
+
+// This is to deal with changes brought by macOS 14.
+
+private extension NSApplication {
+  func popup() {
+    #if compiler(>=5.9) && canImport(AppKit, _version: "14.0")
+      if #available(macOS 14.0, *) {
+        NSApp.activate()
+      } else {
+        NSApp.activate(ignoringOtherApps: true)
+      }
+    #else
+      NSApp.activate(ignoringOtherApps: true)
+    #endif
+  }
+}
diff --git a/Installer/AppDelegate_Extension.swift b/Installer/AppDelegate_Extension.swift
index c8d2de1d..e3f42e86 100644
--- a/Installer/AppDelegate_Extension.swift
+++ b/Installer/AppDelegate_Extension.swift
@@ -8,7 +8,7 @@
 // marks, or product names of Contributor, except as required to fulfill notice
 // requirements defined in MIT License.
 
-import Cocoa
+import AppKit
 import InputMethodKit
 
 extension AppDelegate {
diff --git a/Packages/Fuziki_NSAttributedTextView/Sources/NSAttributedTextView/NSAttributedTextView.swift b/Packages/Fuziki_NSAttributedTextView/Sources/NSAttributedTextView/NSAttributedTextView.swift
index 971eee52..b0b79248 100644
--- a/Packages/Fuziki_NSAttributedTextView/Sources/NSAttributedTextView/NSAttributedTextView.swift
+++ b/Packages/Fuziki_NSAttributedTextView/Sources/NSAttributedTextView/NSAttributedTextView.swift
@@ -5,7 +5,7 @@
 // Ref: https://qiita.com/fuziki/items/b31055a69330a3ce55a5
 // Modified by The vChewing Project in order to use it with AppKit.
 
-import Cocoa
+import AppKit
 import CocoaExtension
 import SwiftUI
 
diff --git a/Packages/Jad_BookmarkManager/Sources/BookmarkManager/BookmarkManager.swift b/Packages/Jad_BookmarkManager/Sources/BookmarkManager/BookmarkManager.swift
index 2797864f..abc60b64 100644
--- a/Packages/Jad_BookmarkManager/Sources/BookmarkManager/BookmarkManager.swift
+++ b/Packages/Jad_BookmarkManager/Sources/BookmarkManager/BookmarkManager.swift
@@ -1,7 +1,7 @@
 //  Ref: https://stackoverflow.com/a/61695824
 //  License: https://creativecommons.org/licenses/by-sa/4.0/
 
-import Cocoa
+import AppKit
 
 public class BookmarkManager {
   public static let shared = BookmarkManager()
diff --git a/Packages/Qwertyyb_ShiftKeyUpChecker/Sources/ShiftKeyUpChecker/ShiftKeyUpChecker.swift b/Packages/Qwertyyb_ShiftKeyUpChecker/Sources/ShiftKeyUpChecker/ShiftKeyUpChecker.swift
index 82d2f3e2..9a64fc3e 100644
--- a/Packages/Qwertyyb_ShiftKeyUpChecker/Sources/ShiftKeyUpChecker/ShiftKeyUpChecker.swift
+++ b/Packages/Qwertyyb_ShiftKeyUpChecker/Sources/ShiftKeyUpChecker/ShiftKeyUpChecker.swift
@@ -2,8 +2,8 @@
 // ====================
 // This code is released under the MIT license (SPDX-License-Identifier: MIT)
 
+import AppKit
 import Carbon
-import Cocoa
 
 private extension Date {
   static func - (lhs: Date, rhs: Date) -> TimeInterval {
diff --git a/Packages/ShapsBenkau_SwiftUIBackports/Sources/SwiftUIBackports/Internal/Environment+String.swift b/Packages/ShapsBenkau_SwiftUIBackports/Sources/SwiftUIBackports/Internal/Environment+String.swift
index 8ca4c53b..1635fc45 100755
--- a/Packages/ShapsBenkau_SwiftUIBackports/Sources/SwiftUIBackports/Internal/Environment+String.swift
+++ b/Packages/ShapsBenkau_SwiftUIBackports/Sources/SwiftUIBackports/Internal/Environment+String.swift
@@ -99,8 +99,8 @@ private extension EnvironmentValues {
 @available(macOS 10.15, *)
 @propertyWrapper
 internal struct StringlyTypedEnvironment<Value> {
-  final class Store<Value>: ObservableObject {
-    var value: Value?
+  final class Store<StoredValue>: ObservableObject {
+    var value: StoredValue?
   }
 
   @Environment(\.self) private var env
diff --git a/Packages/Sindresorhus_SSPreferences/Sources/SSPreferences/SegmentedControlStyleViewController.swift b/Packages/Sindresorhus_SSPreferences/Sources/SSPreferences/SegmentedControlStyleViewController.swift
index e47ac695..98bc4513 100644
--- a/Packages/Sindresorhus_SSPreferences/Sources/SSPreferences/SegmentedControlStyleViewController.swift
+++ b/Packages/Sindresorhus_SSPreferences/Sources/SSPreferences/SegmentedControlStyleViewController.swift
@@ -2,7 +2,7 @@
 // ====================
 // This code is released under the MIT license (SPDX-License-Identifier: MIT)
 
-import Cocoa
+import AppKit
 
 extension NSToolbarItem.Identifier {
   static let toolbarSegmentedControlItem = Self("toolbarSegmentedControlItem")
diff --git a/Packages/Sindresorhus_SSPreferences/Sources/SSPreferences/SettingsPane.swift b/Packages/Sindresorhus_SSPreferences/Sources/SSPreferences/SettingsPane.swift
index 2ed5b2c5..8d2dd5eb 100644
--- a/Packages/Sindresorhus_SSPreferences/Sources/SSPreferences/SettingsPane.swift
+++ b/Packages/Sindresorhus_SSPreferences/Sources/SSPreferences/SettingsPane.swift
@@ -2,7 +2,7 @@
 // ====================
 // This code is released under the MIT license (SPDX-License-Identifier: MIT)
 
-import Cocoa
+import AppKit
 
 public extension Settings {
   struct PaneIdentifier: Hashable, RawRepresentable, Codable {
diff --git a/Packages/Sindresorhus_SSPreferences/Sources/SSPreferences/SettingsStyleController.swift b/Packages/Sindresorhus_SSPreferences/Sources/SSPreferences/SettingsStyleController.swift
index 59c25330..23d6b27f 100644
--- a/Packages/Sindresorhus_SSPreferences/Sources/SSPreferences/SettingsStyleController.swift
+++ b/Packages/Sindresorhus_SSPreferences/Sources/SSPreferences/SettingsStyleController.swift
@@ -2,7 +2,7 @@
 // ====================
 // This code is released under the MIT license (SPDX-License-Identifier: MIT)
 
-import Cocoa
+import AppKit
 
 protocol SettingsStyleController: AnyObject {
   var delegate: SettingsStyleControllerDelegate? { get set }
diff --git a/Packages/Sindresorhus_SSPreferences/Sources/SSPreferences/SettingsTabViewController.swift b/Packages/Sindresorhus_SSPreferences/Sources/SSPreferences/SettingsTabViewController.swift
index 6ae04db5..ce64cf46 100644
--- a/Packages/Sindresorhus_SSPreferences/Sources/SSPreferences/SettingsTabViewController.swift
+++ b/Packages/Sindresorhus_SSPreferences/Sources/SSPreferences/SettingsTabViewController.swift
@@ -2,7 +2,7 @@
 // ====================
 // This code is released under the MIT license (SPDX-License-Identifier: MIT)
 
-import Cocoa
+import AppKit
 
 final class SettingsTabViewController: NSViewController, SettingsStyleControllerDelegate {
   private var activeTab: Int?
diff --git a/Packages/Sindresorhus_SSPreferences/Sources/SSPreferences/SettingsWindowController.swift b/Packages/Sindresorhus_SSPreferences/Sources/SSPreferences/SettingsWindowController.swift
index 3b4ca7f7..aae5df7b 100644
--- a/Packages/Sindresorhus_SSPreferences/Sources/SSPreferences/SettingsWindowController.swift
+++ b/Packages/Sindresorhus_SSPreferences/Sources/SSPreferences/SettingsWindowController.swift
@@ -2,7 +2,7 @@
 // ====================
 // This code is released under the MIT license (SPDX-License-Identifier: MIT)
 
-import Cocoa
+import AppKit
 
 extension NSWindow.FrameAutosaveName {
   static let settings: NSWindow.FrameAutosaveName = "com.sindresorhus.Preferences.FrameAutosaveName"
@@ -100,7 +100,15 @@ public final class SettingsWindowController: NSWindowController {
 
     showWindow(self)
     restoreWindowPosition()
-    NSApp.activate(ignoringOtherApps: true)
+    #if compiler(>=5.9) && canImport(AppKit, _version: "14.0")
+      if #available(macOS 14.0, *) {
+        NSApp.activate()
+      } else {
+        NSApp.activate(ignoringOtherApps: true)
+      }
+    #else
+      NSApp.activate(ignoringOtherApps: true)
+    #endif
   }
 
   private func restoreWindowPosition() {
diff --git a/Packages/Sindresorhus_SSPreferences/Sources/SSPreferences/Style.swift b/Packages/Sindresorhus_SSPreferences/Sources/SSPreferences/Style.swift
index fdc7543c..d37cc819 100644
--- a/Packages/Sindresorhus_SSPreferences/Sources/SSPreferences/Style.swift
+++ b/Packages/Sindresorhus_SSPreferences/Sources/SSPreferences/Style.swift
@@ -2,7 +2,7 @@
 // ====================
 // This code is released under the MIT license (SPDX-License-Identifier: MIT)
 
-import Cocoa
+import AppKit
 
 public extension Settings {
   enum Style {
diff --git a/Packages/Sindresorhus_SSPreferences/Sources/SSPreferences/ToolbarItemStyleViewController.swift b/Packages/Sindresorhus_SSPreferences/Sources/SSPreferences/ToolbarItemStyleViewController.swift
index 4ec74767..9b2d41ad 100644
--- a/Packages/Sindresorhus_SSPreferences/Sources/SSPreferences/ToolbarItemStyleViewController.swift
+++ b/Packages/Sindresorhus_SSPreferences/Sources/SSPreferences/ToolbarItemStyleViewController.swift
@@ -2,7 +2,7 @@
 // ====================
 // This code is released under the MIT license (SPDX-License-Identifier: MIT)
 
-import Cocoa
+import AppKit
 
 final class ToolbarItemStyleViewController: NSObject, SettingsStyleController {
   let toolbar: NSToolbar
diff --git a/Packages/vChewing_CandidateWindow/Sources/CandidateWindow/CandidateCellData_Core.swift b/Packages/vChewing_CandidateWindow/Sources/CandidateWindow/CandidateCellData_Core.swift
index 67799c74..29983e22 100644
--- a/Packages/vChewing_CandidateWindow/Sources/CandidateWindow/CandidateCellData_Core.swift
+++ b/Packages/vChewing_CandidateWindow/Sources/CandidateWindow/CandidateCellData_Core.swift
@@ -6,7 +6,7 @@
 // marks, or product names of Contributor, except as required to fulfill notice
 // requirements defined in MIT License.
 
-import Cocoa
+import AppKit
 import Shared
 import SwiftUI
 import SwiftUIBackports
diff --git a/Packages/vChewing_CandidateWindow/Sources/CandidateWindow/CandidatePool_CocoaImpl.swift b/Packages/vChewing_CandidateWindow/Sources/CandidateWindow/CandidatePool_CocoaImpl.swift
index 7a8c07dd..1d8ab923 100644
--- a/Packages/vChewing_CandidateWindow/Sources/CandidateWindow/CandidatePool_CocoaImpl.swift
+++ b/Packages/vChewing_CandidateWindow/Sources/CandidateWindow/CandidatePool_CocoaImpl.swift
@@ -6,7 +6,7 @@
 // marks, or product names of Contributor, except as required to fulfill notice
 // requirements defined in MIT License.
 
-import Cocoa
+import AppKit
 
 // MARK: - Using One Single NSAttributedString.
 
diff --git a/Packages/vChewing_CandidateWindow/Sources/CandidateWindow/CtlCandidate.swift b/Packages/vChewing_CandidateWindow/Sources/CandidateWindow/CtlCandidate.swift
index 6b9a90d1..2d0d41fd 100644
--- a/Packages/vChewing_CandidateWindow/Sources/CandidateWindow/CtlCandidate.swift
+++ b/Packages/vChewing_CandidateWindow/Sources/CandidateWindow/CtlCandidate.swift
@@ -6,7 +6,7 @@
 // marks, or product names of Contributor, except as required to fulfill notice
 // requirements defined in MIT License.
 
-import Cocoa
+import AppKit
 import Shared
 
 open class CtlCandidate: NSWindowController, CtlCandidateProtocol {
diff --git a/Packages/vChewing_CandidateWindow/Sources/CandidateWindow/TDKCandidates/CtlCandidateTDK.swift b/Packages/vChewing_CandidateWindow/Sources/CandidateWindow/TDKCandidates/CtlCandidateTDK.swift
index e5571980..465cb43c 100644
--- a/Packages/vChewing_CandidateWindow/Sources/CandidateWindow/TDKCandidates/CtlCandidateTDK.swift
+++ b/Packages/vChewing_CandidateWindow/Sources/CandidateWindow/TDKCandidates/CtlCandidateTDK.swift
@@ -6,7 +6,7 @@
 // marks, or product names of Contributor, except as required to fulfill notice
 // requirements defined in MIT License.
 
-import Cocoa
+import AppKit
 import CocoaExtension
 import Shared
 import SwiftExtension
diff --git a/Packages/vChewing_CandidateWindow/Sources/CandidateWindow/TDKCandidates/VwrCandidateTDK_Cocoa.swift b/Packages/vChewing_CandidateWindow/Sources/CandidateWindow/TDKCandidates/VwrCandidateTDK_Cocoa.swift
index 4afbeb67..41cf6004 100644
--- a/Packages/vChewing_CandidateWindow/Sources/CandidateWindow/TDKCandidates/VwrCandidateTDK_Cocoa.swift
+++ b/Packages/vChewing_CandidateWindow/Sources/CandidateWindow/TDKCandidates/VwrCandidateTDK_Cocoa.swift
@@ -6,7 +6,7 @@
 // marks, or product names of Contributor, except as required to fulfill notice
 // requirements defined in MIT License.
 
-import Cocoa
+import AppKit
 import Shared
 
 /// 田所選字窗的 Cocoa 版本，繪製效率不受 SwiftUI 的限制。
diff --git a/Packages/vChewing_CandidateWindow/Sources/CandidateWindow/TDKCandidates/VwrCandidateTDK_SwiftUI.swift b/Packages/vChewing_CandidateWindow/Sources/CandidateWindow/TDKCandidates/VwrCandidateTDK_SwiftUI.swift
index bfbdcb32..ee280ede 100644
--- a/Packages/vChewing_CandidateWindow/Sources/CandidateWindow/TDKCandidates/VwrCandidateTDK_SwiftUI.swift
+++ b/Packages/vChewing_CandidateWindow/Sources/CandidateWindow/TDKCandidates/VwrCandidateTDK_SwiftUI.swift
@@ -6,7 +6,7 @@
 // marks, or product names of Contributor, except as required to fulfill notice
 // requirements defined in MIT License.
 
-import Cocoa
+import AppKit
 import Shared
 import SwiftUI
 import SwiftUIBackports
diff --git a/Packages/vChewing_CandidateWindow/Tests/CandidateWindowTests/CandidatePoolTests.swift b/Packages/vChewing_CandidateWindow/Tests/CandidateWindowTests/CandidatePoolTests.swift
index 7521006d..43e4e029 100644
--- a/Packages/vChewing_CandidateWindow/Tests/CandidateWindowTests/CandidatePoolTests.swift
+++ b/Packages/vChewing_CandidateWindow/Tests/CandidateWindowTests/CandidatePoolTests.swift
@@ -6,7 +6,7 @@
 // marks, or product names of Contributor, except as required to fulfill notice
 // requirements defined in MIT License.
 
-import Cocoa
+import AppKit
 import XCTest
 
 @testable import CandidateWindow
diff --git a/Packages/vChewing_CocoaExtension/Sources/CocoaExtension/CocoaExtension_Misc.swift b/Packages/vChewing_CocoaExtension/Sources/CocoaExtension/CocoaExtension_Misc.swift
index 9d15c989..7d913465 100644
--- a/Packages/vChewing_CocoaExtension/Sources/CocoaExtension/CocoaExtension_Misc.swift
+++ b/Packages/vChewing_CocoaExtension/Sources/CocoaExtension/CocoaExtension_Misc.swift
@@ -6,7 +6,7 @@
 // marks, or product names of Contributor, except as required to fulfill notice
 // requirements defined in MIT License.
 
-import Cocoa
+import AppKit
 import SwiftExtension
 
 // MARK: - NSSize extension
@@ -238,3 +238,21 @@ public extension NSApplication {
     return machine == "arm64"
   }
 }
+
+// MARK: - NSApp Activation Helper
+
+// This is to deal with changes brought by macOS 14.
+
+public extension NSApplication {
+  func popup() {
+    #if compiler(>=5.9) && canImport(AppKit, _version: "14.0")
+      if #available(macOS 14.0, *) {
+        NSApp.activate()
+      } else {
+        NSApp.activate(ignoringOtherApps: true)
+      }
+    #else
+      NSApp.activate(ignoringOtherApps: true)
+    #endif
+  }
+}
diff --git a/Packages/vChewing_CocoaExtension/Sources/CocoaExtension/CocoaExtension_NSEvent.swift b/Packages/vChewing_CocoaExtension/Sources/CocoaExtension/CocoaExtension_NSEvent.swift
index a9c92757..74bed8b4 100644
--- a/Packages/vChewing_CocoaExtension/Sources/CocoaExtension/CocoaExtension_NSEvent.swift
+++ b/Packages/vChewing_CocoaExtension/Sources/CocoaExtension/CocoaExtension_NSEvent.swift
@@ -6,7 +6,7 @@
 // marks, or product names of Contributor, except as required to fulfill notice
 // requirements defined in MIT License.
 
-import Cocoa
+import AppKit
 import IMKUtils
 
 // MARK: - NSEvent Extension - Reconstructors
diff --git a/Packages/vChewing_CocoaExtension/Sources/CocoaExtension/CocoaExtension_NSSound.swift b/Packages/vChewing_CocoaExtension/Sources/CocoaExtension/CocoaExtension_NSSound.swift
index 3671a679..b979066f 100644
--- a/Packages/vChewing_CocoaExtension/Sources/CocoaExtension/CocoaExtension_NSSound.swift
+++ b/Packages/vChewing_CocoaExtension/Sources/CocoaExtension/CocoaExtension_NSSound.swift
@@ -6,8 +6,8 @@
 // marks, or product names of Contributor, except as required to fulfill notice
 // requirements defined in MIT License.
 
+import AppKit
 import AVFoundation
-import Cocoa
 
 public extension NSSound {
   static func buzz(fart: Bool = false) {
diff --git a/Packages/vChewing_CocoaExtension/Sources/CocoaExtension/CocoaExtension_NSWindowController.swift b/Packages/vChewing_CocoaExtension/Sources/CocoaExtension/CocoaExtension_NSWindowController.swift
index 52324ec2..a158b95b 100644
--- a/Packages/vChewing_CocoaExtension/Sources/CocoaExtension/CocoaExtension_NSWindowController.swift
+++ b/Packages/vChewing_CocoaExtension/Sources/CocoaExtension/CocoaExtension_NSWindowController.swift
@@ -6,7 +6,7 @@
 // marks, or product names of Contributor, except as required to fulfill notice
 // requirements defined in MIT License.
 
-import Cocoa
+import AppKit
 import InputMethodKit
 
 public extension NSWindowController {
diff --git a/Packages/vChewing_CocoaExtension/Sources/CocoaExtension/CocoaExtension_NSWindowPositioner.swift b/Packages/vChewing_CocoaExtension/Sources/CocoaExtension/CocoaExtension_NSWindowPositioner.swift
index b6d72de7..eee340f5 100644
--- a/Packages/vChewing_CocoaExtension/Sources/CocoaExtension/CocoaExtension_NSWindowPositioner.swift
+++ b/Packages/vChewing_CocoaExtension/Sources/CocoaExtension/CocoaExtension_NSWindowPositioner.swift
@@ -2,7 +2,7 @@
 // Written by Alexis Bridoux - https://github.com/ABridoux
 // Ref: https://gist.github.com/ABridoux/b935c21c7ead92033d39b357fae6366b
 
-import Cocoa
+import AppKit
 import SwiftUI
 
 // MARK: Model
diff --git a/Packages/vChewing_Megrez/Tests/MegrezTests/MegrezTests.swift b/Packages/vChewing_Megrez/Tests/MegrezTests/MegrezTests.swift
index d8823f37..bcd351fb 100644
--- a/Packages/vChewing_Megrez/Tests/MegrezTests/MegrezTests.swift
+++ b/Packages/vChewing_Megrez/Tests/MegrezTests/MegrezTests.swift
@@ -3,7 +3,7 @@
 // ====================
 // This code is released under the MIT license (SPDX-License-Identifier: MIT)
 
-import Cocoa
+import AppKit
 import XCTest
 
 @testable import Megrez
diff --git a/Packages/vChewing_NotifierUI/Sources/NotifierUI/NotifierUI.swift b/Packages/vChewing_NotifierUI/Sources/NotifierUI/NotifierUI.swift
index 79eafd2a..ce00b605 100644
--- a/Packages/vChewing_NotifierUI/Sources/NotifierUI/NotifierUI.swift
+++ b/Packages/vChewing_NotifierUI/Sources/NotifierUI/NotifierUI.swift
@@ -6,7 +6,7 @@
 // marks, or product names of Contributor, except as required to fulfill notice
 // requirements defined in MIT License.
 
-import Cocoa
+import AppKit
 import CocoaExtension
 
 public class Notifier: NSWindowController {
diff --git a/Packages/vChewing_PhraseEditorUI/Sources/PhraseEditorUI/PhraseEditorUI.swift b/Packages/vChewing_PhraseEditorUI/Sources/PhraseEditorUI/PhraseEditorUI.swift
index da785a6c..9d430203 100644
--- a/Packages/vChewing_PhraseEditorUI/Sources/PhraseEditorUI/PhraseEditorUI.swift
+++ b/Packages/vChewing_PhraseEditorUI/Sources/PhraseEditorUI/PhraseEditorUI.swift
@@ -6,7 +6,7 @@
 // marks, or product names of Contributor, except as required to fulfill notice
 // requirements defined in MIT License.
 
-import Cocoa
+import AppKit
 import Combine
 import Foundation
 import LangModelAssembly
diff --git a/Packages/vChewing_PinyinPhonaConverter/Sources/PinyinPhonaConverter/PinyinPhonaConverter.swift b/Packages/vChewing_PinyinPhonaConverter/Sources/PinyinPhonaConverter/PinyinPhonaConverter.swift
index 9a05477a..2b3f34ab 100644
--- a/Packages/vChewing_PinyinPhonaConverter/Sources/PinyinPhonaConverter/PinyinPhonaConverter.swift
+++ b/Packages/vChewing_PinyinPhonaConverter/Sources/PinyinPhonaConverter/PinyinPhonaConverter.swift
@@ -6,7 +6,7 @@
 // marks, or product names of Contributor, except as required to fulfill notice
 // requirements defined in MIT License.
 
-import Cocoa
+import AppKit
 
 public extension String {
   mutating func convertToPhonabets(newToneOne: String = "") {
diff --git a/Packages/vChewing_PopupCompositionBuffer/Sources/PopupCompositionBuffer/PopupCompositionBuffer.swift b/Packages/vChewing_PopupCompositionBuffer/Sources/PopupCompositionBuffer/PopupCompositionBuffer.swift
index 84ce37b7..1d51cce3 100644
--- a/Packages/vChewing_PopupCompositionBuffer/Sources/PopupCompositionBuffer/PopupCompositionBuffer.swift
+++ b/Packages/vChewing_PopupCompositionBuffer/Sources/PopupCompositionBuffer/PopupCompositionBuffer.swift
@@ -6,7 +6,7 @@
 // marks, or product names of Contributor, except as required to fulfill notice
 // requirements defined in MIT License.
 
-import Cocoa
+import AppKit
 import Shared
 
 public class PopupCompositionBuffer: NSWindowController {
diff --git a/Packages/vChewing_Shared/Sources/Shared/Protocols/CtlCandidateProtocol.swift b/Packages/vChewing_Shared/Sources/Shared/Protocols/CtlCandidateProtocol.swift
index 7e8e96f4..5c7f6836 100644
--- a/Packages/vChewing_Shared/Sources/Shared/Protocols/CtlCandidateProtocol.swift
+++ b/Packages/vChewing_Shared/Sources/Shared/Protocols/CtlCandidateProtocol.swift
@@ -6,7 +6,7 @@
 // marks, or product names of Contributor, except as required to fulfill notice
 // requirements defined in MIT License.
 
-import Cocoa
+import AppKit
 
 public protocol CtlCandidateDelegate {
   func candidatePairs(conv: Bool) -> [(keyArray: [String], value: String)]
diff --git a/Packages/vChewing_Shared/Sources/Shared/Protocols/IMEStateProtocol.swift b/Packages/vChewing_Shared/Sources/Shared/Protocols/IMEStateProtocol.swift
index 75d2ba28..85b88da6 100644
--- a/Packages/vChewing_Shared/Sources/Shared/Protocols/IMEStateProtocol.swift
+++ b/Packages/vChewing_Shared/Sources/Shared/Protocols/IMEStateProtocol.swift
@@ -6,7 +6,7 @@
 // marks, or product names of Contributor, except as required to fulfill notice
 // requirements defined in MIT License.
 
-import Cocoa
+import AppKit
 import InputMethodKit
 
 // 所有 IMEState 均遵守該協定：
diff --git a/Packages/vChewing_Shared/Sources/Shared/Protocols/InputSignalProtocol.swift b/Packages/vChewing_Shared/Sources/Shared/Protocols/InputSignalProtocol.swift
index c382d641..ce61cf87 100644
--- a/Packages/vChewing_Shared/Sources/Shared/Protocols/InputSignalProtocol.swift
+++ b/Packages/vChewing_Shared/Sources/Shared/Protocols/InputSignalProtocol.swift
@@ -6,7 +6,7 @@
 // marks, or product names of Contributor, except as required to fulfill notice
 // requirements defined in MIT License.
 
-import Cocoa
+import AppKit
 import CocoaExtension
 
 extension NSEvent: InputSignalProtocol {}
diff --git a/Packages/vChewing_TooltipUI/Sources/TooltipUI/TooltipUI.swift b/Packages/vChewing_TooltipUI/Sources/TooltipUI/TooltipUI.swift
index 248f122d..4d3fac87 100644
--- a/Packages/vChewing_TooltipUI/Sources/TooltipUI/TooltipUI.swift
+++ b/Packages/vChewing_TooltipUI/Sources/TooltipUI/TooltipUI.swift
@@ -6,7 +6,7 @@
 // marks, or product names of Contributor, except as required to fulfill notice
 // requirements defined in MIT License.
 
-import Cocoa
+import AppKit
 import CocoaExtension
 import NSAttributedTextView
 import Shared
diff --git a/Packages/vChewing_Uninstaller/Sources/Uninstaller/Uninstaller.swift b/Packages/vChewing_Uninstaller/Sources/Uninstaller/Uninstaller.swift
index a74afd93..4dfbfd9c 100644
--- a/Packages/vChewing_Uninstaller/Sources/Uninstaller/Uninstaller.swift
+++ b/Packages/vChewing_Uninstaller/Sources/Uninstaller/Uninstaller.swift
@@ -6,7 +6,7 @@
 // marks, or product names of Contributor, except as required to fulfill notice
 // requirements defined in MIT License.
 
-import Cocoa
+import AppKit
 import CocoaExtension
 
 public enum Uninstaller {
diff --git a/Packages/vChewing_UpdateSputnik/Sources/UpdateSputnik/UpdateSputnik.swift b/Packages/vChewing_UpdateSputnik/Sources/UpdateSputnik/UpdateSputnik.swift
index 0424b1d2..76c78e17 100644
--- a/Packages/vChewing_UpdateSputnik/Sources/UpdateSputnik/UpdateSputnik.swift
+++ b/Packages/vChewing_UpdateSputnik/Sources/UpdateSputnik/UpdateSputnik.swift
@@ -6,7 +6,7 @@
 // marks, or product names of Contributor, except as required to fulfill notice
 // requirements defined in MIT License.
 
-import Cocoa
+import AppKit
 
 public class UpdateSputnik {
   public static let shared: UpdateSputnik = .init()
@@ -113,7 +113,7 @@ public class UpdateSputnik {
       alert.informativeText = NSLocalizedString("You are already using the latest version.", comment: "")
       alert.addButton(withTitle: NSLocalizedString("OK", comment: ""))
       alert.runModal()
-      NSApp.activate(ignoringOtherApps: true)
+      NSApp.popup()
       return
     }
 
@@ -144,7 +144,7 @@ public class UpdateSputnik {
     }
 
     let result = alert.runModal()
-    NSApp.activate(ignoringOtherApps: true)
+    NSApp.popup()
     switch result {
     case .alertFirstButtonReturn:
       DispatchQueue.main.async {
@@ -172,6 +172,24 @@ public class UpdateSputnik {
     alert.informativeText = content
     alert.addButton(withTitle: NSLocalizedString("OK", comment: ""))
     alert.runModal()
-    NSApp.activate(ignoringOtherApps: true)
+    NSApp.popup()
+  }
+}
+
+// MARK: - NSApp Activation Helper
+
+// This is to deal with changes brought by macOS 14.
+
+private extension NSApplication {
+  func popup() {
+    #if compiler(>=5.9) && canImport(AppKit, _version: "14.0")
+      if #available(macOS 14.0, *) {
+        NSApp.activate()
+      } else {
+        NSApp.activate(ignoringOtherApps: true)
+      }
+    #else
+      NSApp.activate(ignoringOtherApps: true)
+    #endif
   }
 }
diff --git a/Source/Modules/AppDelegate.swift b/Source/Modules/AppDelegate.swift
index 96779163..43752052 100644
--- a/Source/Modules/AppDelegate.swift
+++ b/Source/Modules/AppDelegate.swift
@@ -130,7 +130,7 @@ public extension AppDelegate {
     }
     alert.addButton(withTitle: NSLocalizedString("Not Now", comment: ""))
     let result = alert.runModal()
-    NSApp.activate(ignoringOtherApps: true)
+    NSApp.popup()
     if result == NSApplication.ModalResponse.alertFirstButtonReturn {
       NSWorkspace.shared.openFile(
         LMMgr.dataFolderPath(isDefaultFolder: true), withApplication: "Finder"
@@ -167,6 +167,6 @@ public extension AppDelegate {
   // New About Window
   @IBAction func about(_: Any) {
     CtlAboutWindow.show()
-    NSApp.activate(ignoringOtherApps: true)
+    NSApp.popup()
   }
 }
diff --git a/Source/Modules/LMMgr_Utilities.swift b/Source/Modules/LMMgr_Utilities.swift
index b068899d..f07a58cf 100644
--- a/Source/Modules/LMMgr_Utilities.swift
+++ b/Source/Modules/LMMgr_Utilities.swift
@@ -302,7 +302,7 @@ public extension LMMgr {
         alert.informativeText = content
         alert.addButton(withTitle: NSLocalizedString("OK", comment: ""))
         alert.runModal()
-        NSApp.activate(ignoringOtherApps: true)
+        NSApp.popup()
       }
       return false
     }
diff --git a/Source/Modules/SessionCtl_Core.swift b/Source/Modules/SessionCtl_Core.swift
index 68753498..1a898266 100644
--- a/Source/Modules/SessionCtl_Core.swift
+++ b/Source/Modules/SessionCtl_Core.swift
@@ -358,7 +358,7 @@ public extension SessionCtl {
         break modeCheck
       }
       let result = sharedAlertForInputModeToggling.runModal()
-      NSApp.activate(ignoringOtherApps: true)
+      NSApp.popup()
       if result == NSApplication.ModalResponse.alertFirstButtonReturn {
         neta.activate()
       }
diff --git a/Source/Modules/SessionCtl_Menu.swift b/Source/Modules/SessionCtl_Menu.swift
index 8765a9e7..19821dba 100644
--- a/Source/Modules/SessionCtl_Menu.swift
+++ b/Source/Modules/SessionCtl_Menu.swift
@@ -225,11 +225,11 @@ public extension SessionCtl {
       // CtlPrefUIShared.shared.controller.window?.setPosition(vertical: .top, horizontal: .right, padding: 20)
       default: CtlPrefUI.show()
       }
-      NSApp.activate(ignoringOtherApps: true)
+      NSApp.popup()
       return
     }
     CtlPrefWindow.show()
-    NSApp.activate(ignoringOtherApps: true)
+    NSApp.popup()
   }
 
   @objc func showCheatSheet(_: Any? = nil) {
@@ -241,7 +241,7 @@ public extension SessionCtl {
 
   @objc func showClientListMgr(_: Any? = nil) {
     CtlClientListMgr.show()
-    NSApp.activate(ignoringOtherApps: true)
+    NSApp.popup()
   }
 
   @objc func toggleCassetteMode(_: Any? = nil) {
@@ -253,7 +253,7 @@ public extension SessionCtl {
         let informativeText = "Please reconfigure the cassette path to a valid one before enabling this mode."
         alert.informativeText = informativeText.localized
         let result = alert.runModal()
-        NSApp.activate(ignoringOtherApps: true)
+        NSApp.popup()
         if result == NSApplication.ModalResponse.alertFirstButtonReturn {
           LMMgr.resetCassettePath()
           PrefMgr.shared.cassetteEnabled = false
@@ -367,7 +367,7 @@ public extension SessionCtl {
   }
 
   @objc func selfTerminate(_: Any? = nil) {
-    NSApp.activate(ignoringOtherApps: true)
+    NSApp.popup()
     NSApp.terminate(nil)
   }
 
@@ -428,6 +428,6 @@ public extension SessionCtl {
 
   @objc func showAbout(_: Any? = nil) {
     CtlAboutWindow.show()
-    NSApp.activate(ignoringOtherApps: true)
+    NSApp.popup()
   }
 }
diff --git a/Source/Modules/UIModules/PrefUI/CtlPrefUI.swift b/Source/Modules/UIModules/PrefUI/CtlPrefUI.swift
index 77e60574..f0cd3b92 100644
--- a/Source/Modules/UIModules/PrefUI/CtlPrefUI.swift
+++ b/Source/Modules/UIModules/PrefUI/CtlPrefUI.swift
@@ -67,7 +67,7 @@ class CtlPrefUI: NSWindowController, NSWindowDelegate {
     sharedWindow.orderFrontRegardless() // 逼著視窗往最前方顯示
     sharedWindow.level = .statusBar
     shared.showWindow(shared)
-    NSApp.activate(ignoringOtherApps: true)
+    NSApp.popup()
   }
 
   private var currentLanguageSelectItem: NSMenuItem?
diff --git a/Source/Modules/UIModules/PrefUITabs.swift b/Source/Modules/UIModules/PrefUITabs.swift
index d78fe809..fc732244 100644
--- a/Source/Modules/UIModules/PrefUITabs.swift
+++ b/Source/Modules/UIModules/PrefUITabs.swift
@@ -6,7 +6,7 @@
 // marks, or product names of Contributor, except as required to fulfill notice
 // requirements defined in MIT License.
 
-import Cocoa
+import AppKit
 import Shared
 
 enum PrefUITabs: String, CaseIterable {
diff --git a/Source/Modules/WindowControllers/CtlAboutWindow.swift b/Source/Modules/WindowControllers/CtlAboutWindow.swift
index db883af2..87f43a34 100644
--- a/Source/Modules/WindowControllers/CtlAboutWindow.swift
+++ b/Source/Modules/WindowControllers/CtlAboutWindow.swift
@@ -6,7 +6,7 @@
 // marks, or product names of Contributor, except as required to fulfill notice
 // requirements defined in MIT License.
 
-import Cocoa
+import AppKit
 
 class CtlAboutWindow: NSWindowController {
   @IBOutlet var appVersionLabel: NSTextField!
@@ -23,7 +23,7 @@ class CtlAboutWindow: NSWindowController {
     sharedWindow.level = .statusBar
     sharedWindow.titlebarAppearsTransparent = true
     shared.showWindow(shared)
-    NSApp.activate(ignoringOtherApps: true)
+    NSApp.popup()
   }
 
   override func windowDidLoad() {
diff --git a/Source/Modules/WindowControllers/CtlClientListMgr.swift b/Source/Modules/WindowControllers/CtlClientListMgr.swift
index 34b6c341..c5f88c0f 100644
--- a/Source/Modules/WindowControllers/CtlClientListMgr.swift
+++ b/Source/Modules/WindowControllers/CtlClientListMgr.swift
@@ -6,7 +6,7 @@
 // marks, or product names of Contributor, except as required to fulfill notice
 // requirements defined in MIT License.
 
-import Cocoa
+import AppKit
 
 class CtlClientListMgr: NSWindowController, NSTableViewDelegate, NSTableViewDataSource {
   @IBOutlet var tblClients: NSTableView!
@@ -24,7 +24,7 @@ class CtlClientListMgr: NSWindowController, NSTableViewDelegate, NSTableViewData
     sharedWindow.level = .statusBar
     sharedWindow.titlebarAppearsTransparent = true
     shared.showWindow(shared)
-    NSApp.activate(ignoringOtherApps: true)
+    NSApp.popup()
   }
 
   override func windowDidLoad() {
diff --git a/Source/Modules/WindowControllers/CtlPrefWindow.swift b/Source/Modules/WindowControllers/CtlPrefWindow.swift
index bf2c9143..014c6944 100644
--- a/Source/Modules/WindowControllers/CtlPrefWindow.swift
+++ b/Source/Modules/WindowControllers/CtlPrefWindow.swift
@@ -73,7 +73,7 @@ class CtlPrefWindow: NSWindowController, NSWindowDelegate {
     sharedWindow.level = .statusBar
     shared.showWindow(shared)
     if resetPhraseEditor { shared.initPhraseEditor() }
-    NSApp.activate(ignoringOtherApps: true)
+    NSApp.popup()
   }
 
   private var currentLanguageSelectItem: NSMenuItem?
diff --git a/Source/Modules/WindowControllers/CtlRevLookupWindow.swift b/Source/Modules/WindowControllers/CtlRevLookupWindow.swift
index ca525fac..be37568e 100644
--- a/Source/Modules/WindowControllers/CtlRevLookupWindow.swift
+++ b/Source/Modules/WindowControllers/CtlRevLookupWindow.swift
@@ -6,7 +6,7 @@
 // marks, or product names of Contributor, except as required to fulfill notice
 // requirements defined in MIT License.
 
-import Cocoa
+import AppKit
 import LangModelAssembly
 
 class CtlRevLookupWindow: NSWindowController, NSWindowDelegate {
@@ -22,7 +22,7 @@ class CtlRevLookupWindow: NSWindowController, NSWindowDelegate {
     window.level = .statusBar
     window.titlebarAppearsTransparent = true
     shared.showWindow(shared)
-    NSApp.activate(ignoringOtherApps: true)
+    NSApp.popup()
   }
 }
 
diff --git a/Source/Modules/main.swift b/Source/Modules/main.swift
index 8afc7b52..07186e0b 100644
--- a/Source/Modules/main.swift
+++ b/Source/Modules/main.swift
@@ -6,7 +6,7 @@
 // marks, or product names of Contributor, except as required to fulfill notice
 // requirements defined in MIT License.
 
-import Cocoa
+import AppKit
 import CocoaExtension
 import IMKUtils
 import InputMethodKit