diff --git a/src/plugins/coreplugin/externaltool.cpp b/src/plugins/coreplugin/externaltool.cpp
index 90108b600ae610d726129200f8169d3973127179..58aa7b3ea489175efdfdcd8bc157fd7c593be4ef 100644
--- a/src/plugins/coreplugin/externaltool.cpp
+++ b/src/plugins/coreplugin/externaltool.cpp
@@ -944,6 +944,5 @@ void ExternalToolManager::writeSettings()
 
 void ExternalToolManager::openPreferences()
 {
-    ICore::showOptionsDialog(QLatin1String(Core::Constants::SETTINGS_CATEGORY_CORE),
-                                         QLatin1String(Core::Constants::SETTINGS_ID_TOOLS));
+    ICore::showOptionsDialog(Constants::SETTINGS_CATEGORY_CORE, Constants::SETTINGS_ID_TOOLS);
 }
diff --git a/src/plugins/coreplugin/fileutils.cpp b/src/plugins/coreplugin/fileutils.cpp
index 54dd77760538fde29a1b401b9a57d82d05cda1ba..58ee844d741057ea65d1e33c8d5dc421a4b993a0 100644
--- a/src/plugins/coreplugin/fileutils.cpp
+++ b/src/plugins/coreplugin/fileutils.cpp
@@ -71,10 +71,8 @@ static void showGraphicalShellError(QWidget *parent, const QString &app, const Q
     QAbstractButton *settingsButton = mbox.addButton(QApplication::translate("Core::Internal", "Settings..."),
                                                      QMessageBox::ActionRole);
     mbox.exec();
-    if (mbox.clickedButton() == settingsButton) {
-        ICore::showOptionsDialog(QLatin1String(Constants::SETTINGS_CATEGORY_CORE),
-                                 QLatin1String(Constants::SETTINGS_ID_ENVIRONMENT));
-    }
+    if (mbox.clickedButton() == settingsButton)
+        ICore::showOptionsDialog(Constants::SETTINGS_CATEGORY_CORE, Constants::SETTINGS_ID_ENVIRONMENT);
 }
 
 void FileUtils::showInGraphicalShell(QWidget *parent, const QString &pathIn)
diff --git a/src/plugins/coreplugin/icore.cpp b/src/plugins/coreplugin/icore.cpp
index 3029f83a629e9246c2de9fba6c4df246603a8696..47f4ff0fb18c184a2523124f916f199c970bbaa4 100644
--- a/src/plugins/coreplugin/icore.cpp
+++ b/src/plugins/coreplugin/icore.cpp
@@ -393,7 +393,7 @@ void ICore::showNewItemDialog(const QString &title,
     m_mainwindow->showNewItemDialog(title, wizards, defaultLocation, extraVariables);
 }
 
-bool ICore::showOptionsDialog(const QString &group, const QString &page, QWidget *parent)
+bool ICore::showOptionsDialog(const Id group, const Id page, QWidget *parent)
 {
     return m_mainwindow->showOptionsDialog(group, page, parent);
 }
@@ -401,7 +401,7 @@ bool ICore::showOptionsDialog(const QString &group, const QString &page, QWidget
 bool ICore::showWarningWithOptions(const QString &title, const QString &text,
                                    const QString &details,
                                    Id settingsCategory,
-                                   const QString &settingsId,
+                                   Id settingsId,
                                    QWidget *parent)
 {
     return m_mainwindow->showWarningWithOptions(title, text,
diff --git a/src/plugins/coreplugin/icore.h b/src/plugins/coreplugin/icore.h
index 99d4b338396ba7caf280c07d66e2bf9b3c5f2d0d..3326332f06245ce305de0468b44644c4f5decab2 100644
--- a/src/plugins/coreplugin/icore.h
+++ b/src/plugins/coreplugin/icore.h
@@ -82,14 +82,12 @@ public:
                                   const QString &defaultLocation = QString(),
                                   const QVariantMap &extraVariables = QVariantMap());
 
-    static bool showOptionsDialog(const QString &group = QString(),
-                                  const QString &page = QString(),
-                                  QWidget *parent = 0);
+    static bool showOptionsDialog(Id group, Id page, QWidget *parent = 0);
 
     static bool showWarningWithOptions(const QString &title, const QString &text,
                                        const QString &details = QString(),
                                        Id settingsCategory = Id(),
-                                       const QString &settingsId = QString(),
+                                       Id settingsId = Id(),
                                        QWidget *parent = 0);
 
     static QT_DEPRECATED ActionManager *actionManager(); // Use Actionmanager::... directly.
diff --git a/src/plugins/coreplugin/mainwindow.cpp b/src/plugins/coreplugin/mainwindow.cpp
index 1e9814721eaeb91ee07280c2982a84207a4640ea..8106095f388c2bf39665de52cccfdc17afe087e9 100644
--- a/src/plugins/coreplugin/mainwindow.cpp
+++ b/src/plugins/coreplugin/mainwindow.cpp
@@ -960,14 +960,12 @@ void MainWindow::showNewItemDialog(const QString &title,
     wizard->runWizard(path, this, selectedPlatform, extraVariables);
 }
 
-bool MainWindow::showOptionsDialog(const QString &category,
-                                   const QString &page,
-                                   QWidget *parent)
+bool MainWindow::showOptionsDialog(Id category, Id page, QWidget *parent)
 {
     emit m_coreImpl->optionsDialogRequested();
     if (!parent)
         parent = this;
-    SettingsDialog *dialog = SettingsDialog::getSettingsDialog(parent, category, page);
+    SettingsDialog *dialog = SettingsDialog::getSettingsDialog(parent, category.toString(), page.toString());
     return dialog->execDialog();
 }
 
@@ -1349,7 +1347,7 @@ bool MainWindow::showWarningWithOptions(const QString &title,
                                         const QString &text,
                                         const QString &details,
                                         Id settingsCategory,
-                                        const QString &settingsId,
+                                        Id settingsId,
                                         QWidget *parent)
 {
     if (parent == 0)
@@ -1359,11 +1357,10 @@ bool MainWindow::showWarningWithOptions(const QString &title,
     if (!details.isEmpty())
         msgBox.setDetailedText(details);
     QAbstractButton *settingsButton = 0;
-    if (!settingsId.isEmpty() || settingsCategory.isValid())
+    if (settingsId.isValid() || settingsCategory.isValid())
         settingsButton = msgBox.addButton(tr("Settings..."), QMessageBox::AcceptRole);
     msgBox.exec();
-    if (settingsButton && msgBox.clickedButton() == settingsButton) {
-        return showOptionsDialog(settingsCategory.toString(), settingsId);
-    }
+    if (settingsButton && msgBox.clickedButton() == settingsButton)
+        return showOptionsDialog(settingsCategory, settingsId);
     return false;
 }
diff --git a/src/plugins/coreplugin/mainwindow.h b/src/plugins/coreplugin/mainwindow.h
index b895fb39c4a18fecf55da74f9c1bc9ad9bca18d6..c96e7c652cbef886c64c273ebf2bdb1caa53e29b 100644
--- a/src/plugins/coreplugin/mainwindow.h
+++ b/src/plugins/coreplugin/mainwindow.h
@@ -138,14 +138,12 @@ public slots:
                            const QString &defaultLocation = QString(),
                            const QVariantMap &extraVariables = QVariantMap());
 
-    bool showOptionsDialog(const QString &category = QString(),
-                           const QString &page = QString(),
-                           QWidget *parent = 0);
+    bool showOptionsDialog(Id category, Id page, QWidget *parent = 0);
 
     bool showWarningWithOptions(const QString &title, const QString &text,
                                 const QString &details = QString(),
                                 Id settingsCategory = Id(),
-                                const QString &settingsId = QString(),
+                                Id settingsId = Id(),
                                 QWidget *parent = 0);
 
 protected:
diff --git a/src/plugins/cpaster/protocol.cpp b/src/plugins/cpaster/protocol.cpp
index 5e150739ba492086b4f4f7a7ba08eebadace3ca3..36726f253d72d96c2c45c8d6e81914d3d76dac0a 100644
--- a/src/plugins/cpaster/protocol.cpp
+++ b/src/plugins/cpaster/protocol.cpp
@@ -168,8 +168,8 @@ bool Protocol::showConfigurationError(const Protocol *p,
     mb.exec();
     bool rc = false;
     if (mb.clickedButton() == settingsButton)
-        rc = Core::ICore::showOptionsDialog(p->settingsPage()->category(),
-                                                        p->settingsPage()->id(),
+        rc = Core::ICore::showOptionsDialog(Core::Id(p->settingsPage()->category()),
+                                            Core::Id(p->settingsPage()->id()),
                                                         parent);
     return rc;
 }
diff --git a/src/plugins/debugger/debuggerplugin.cpp b/src/plugins/debugger/debuggerplugin.cpp
index b7db2bdb06ab5efb243d7ae9b774da16d3458f6a..f544edd983c1f7ce91eeab785a7afab4e2d469c1 100644
--- a/src/plugins/debugger/debuggerplugin.cpp
+++ b/src/plugins/debugger/debuggerplugin.cpp
@@ -2406,9 +2406,7 @@ void DebuggerPluginPrivate::onModeChanged(IMode *mode)
 
 void DebuggerPluginPrivate::showSettingsDialog()
 {
-    ICore::showOptionsDialog(
-        _(DEBUGGER_SETTINGS_CATEGORY),
-        _(DEBUGGER_COMMON_SETTINGS_ID));
+    ICore::showOptionsDialog(DEBUGGER_SETTINGS_CATEGORY, DEBUGGER_COMMON_SETTINGS_ID);
 }
 
 void DebuggerPluginPrivate::updateDebugWithoutDeployMenu()
diff --git a/src/plugins/debugger/gdb/classicgdbengine.cpp b/src/plugins/debugger/gdb/classicgdbengine.cpp
index daecb17c3da31a025d2193a2b7107fcef245c059..5020296d184e62da641167cd845c9e8234d0d6f9 100644
--- a/src/plugins/debugger/gdb/classicgdbengine.cpp
+++ b/src/plugins/debugger/gdb/classicgdbengine.cpp
@@ -1281,8 +1281,8 @@ static void showQtDumperLibraryWarning(const QString &details)
     dialog.exec();
     if (dialog.clickedButton() == qtPref) {
         Core::ICore::showOptionsDialog(
-            _(ProjectExplorer::Constants::PROJECTEXPLORER_SETTINGS_CATEGORY),
-            _(QtSupport::Constants::QTVERSION_SETTINGS_PAGE_ID));
+            ProjectExplorer::Constants::PROJECTEXPLORER_SETTINGS_CATEGORY,
+            QtSupport::Constants::QTVERSION_SETTINGS_PAGE_ID);
     } else if (dialog.clickedButton() == helperOff) {
         debuggerCore()->action(UseDebuggingHelpers)->setValue(qVariantFromValue(false), false);
     }
diff --git a/src/plugins/debugger/gdb/gdbengine.cpp b/src/plugins/debugger/gdb/gdbengine.cpp
index 1f46d4009ec7a00ce6e9369e663909b0202a277e..ff9641fb2874b05caa21d12b2b0ca129637786d2 100644
--- a/src/plugins/debugger/gdb/gdbengine.cpp
+++ b/src/plugins/debugger/gdb/gdbengine.cpp
@@ -4700,7 +4700,7 @@ void GdbEngine::startGdb(const QStringList &args)
         handleGdbStartFailed();
         handleAdapterStartFailed(
             msgNoGdbBinaryForToolChain(sp.toolChainAbi),
-            _(Constants::DEBUGGER_COMMON_SETTINGS_ID));
+            Constants::DEBUGGER_COMMON_SETTINGS_ID);
         return;
     }
     QStringList gdbArgs;
@@ -4981,13 +4981,13 @@ void GdbEngine::abortDebugger()
 }
 
 void GdbEngine::handleAdapterStartFailed(const QString &msg,
-    const QString &settingsIdHint)
+    Core::Id settingsIdHint)
 {
     QTC_ASSERT(state() == EngineSetupRequested, qDebug() << state());
     showMessage(_("ADAPTER START FAILED"));
     if (!msg.isEmpty()) {
         const QString title = tr("Adapter start failed");
-        if (settingsIdHint.isEmpty()) {
+        if (!settingsIdHint.isValid()) {
             Core::ICore::showWarningWithOptions(title, msg);
         } else {
             Core::ICore::showWarningWithOptions(title, msg, QString(),
diff --git a/src/plugins/debugger/gdb/gdbengine.h b/src/plugins/debugger/gdb/gdbengine.h
index 5ae3da1d99825edf8a6d6b8c12fafbe5ce4e6855..ee41888838d10dc1021471b25729553bff7c85d3 100644
--- a/src/plugins/debugger/gdb/gdbengine.h
+++ b/src/plugins/debugger/gdb/gdbengine.h
@@ -37,6 +37,8 @@
 #include "watchutils.h"
 #include "threaddata.h"
 
+#include <coreplugin/id.h>
+
 #include <QByteArray>
 #include <QProcess>
 #include <QHash>
@@ -239,7 +241,7 @@ protected: ////////// Gdb Process Management //////////
     // Something went wrong with the adapter *before* adapterStarted() was emitted.
     // Make sure to clean up everything before emitting this signal.
     void handleAdapterStartFailed(const QString &msg,
-        const QString &settingsIdHint = QString());
+        Core::Id settingsIdHint = Core::Id());
 
     // This triggers the initial breakpoint synchronization and causes
     // finishInferiorSetup() being called once done.
diff --git a/src/plugins/fakevim/fakevimplugin.cpp b/src/plugins/fakevim/fakevimplugin.cpp
index 04fbd0de0fd8b938a19566182c34372109aaf786..258902095d4d2d123aeafa4495a56a5fe57a8949 100644
--- a/src/plugins/fakevim/fakevimplugin.cpp
+++ b/src/plugins/fakevim/fakevimplugin.cpp
@@ -1191,7 +1191,7 @@ void FakeVimPluginPrivate::maybeReadVimRc()
 
 void FakeVimPluginPrivate::showSettingsDialog()
 {
-    ICore::showOptionsDialog(_(SETTINGS_CATEGORY), _(SETTINGS_ID));
+    ICore::showOptionsDialog(SETTINGS_CATEGORY, SETTINGS_ID);
 }
 
 void FakeVimPluginPrivate::triggerAction(const Id &id)
diff --git a/src/plugins/git/gerrit/gerritoptionspage.cpp b/src/plugins/git/gerrit/gerritoptionspage.cpp
index 7399ed338046e48d402aaf6e1c303c306987ccbf..9941af2c9a8f5d8bb847b78fb1ee6f792af02a14 100644
--- a/src/plugins/git/gerrit/gerritoptionspage.cpp
+++ b/src/plugins/git/gerrit/gerritoptionspage.cpp
@@ -47,15 +47,10 @@ GerritOptionsPage::GerritOptionsPage(const QSharedPointer<GerritParameters> &p,
     : VcsBase::VcsBaseOptionsPage(parent)
     , m_parameters(p)
 {
-    setId(optionsId());
+    setId(QLatin1String("Gerrit"));
     setDisplayName(tr("Gerrit"));
 }
 
-QString GerritOptionsPage::optionsId()
-{
-    return QLatin1String("Gerrit");
-}
-
 QWidget *GerritOptionsPage::createPage(QWidget *parent)
 {
     GerritOptionsWidget *gow = new GerritOptionsWidget(parent);
diff --git a/src/plugins/git/gerrit/gerritoptionspage.h b/src/plugins/git/gerrit/gerritoptionspage.h
index a4111ae83f1a337a01db65548a4f898e5f135cc5..f1993038eeb82b84bdf11f2b529c6e9502ee3c5a 100644
--- a/src/plugins/git/gerrit/gerritoptionspage.h
+++ b/src/plugins/git/gerrit/gerritoptionspage.h
@@ -75,8 +75,6 @@ public:
     GerritOptionsPage(const QSharedPointer<GerritParameters> &p,
                       QObject *parent = 0);
 
-    static QString optionsId();
-
     QWidget *createPage(QWidget *parent);
     void apply();
     void finish() { }
diff --git a/src/plugins/git/gerrit/gerritplugin.cpp b/src/plugins/git/gerrit/gerritplugin.cpp
index 0fdac66320a6128e39f6d5e562334c6733e3d662..cc7671003d4922a8ffc3b4a7659fdddafdcd6822 100644
--- a/src/plugins/git/gerrit/gerritplugin.cpp
+++ b/src/plugins/git/gerrit/gerritplugin.cpp
@@ -360,8 +360,8 @@ void GerritPlugin::openView()
 {
     if (m_dialog.isNull()) {
         while (!m_parameters->isValid()) {
-            const QString group = QLatin1String(VcsBase::Constants::VCS_SETTINGS_CATEGORY);
-            if (!Core::ICore::instance()->showOptionsDialog(group, GerritOptionsPage::optionsId()))
+            const Core::Id group = VcsBase::Constants::VCS_SETTINGS_CATEGORY;
+            if (!Core::ICore::instance()->showOptionsDialog(group, Core::Id("Gerrit")))
                 return;
         }
         GerritDialog *gd = new GerritDialog(m_parameters, Core::ICore::mainWindow());
diff --git a/src/plugins/locator/locatorwidget.cpp b/src/plugins/locator/locatorwidget.cpp
index dc03c2a517d47b098b2ba4f553a5f5eacee371d6..83d0192a120805795eac7b5bb2b0d6a632298295 100644
--- a/src/plugins/locator/locatorwidget.cpp
+++ b/src/plugins/locator/locatorwidget.cpp
@@ -73,6 +73,8 @@
 Q_DECLARE_METATYPE(Locator::ILocatorFilter*)
 Q_DECLARE_METATYPE(Locator::FilterEntry)
 
+using namespace Core;
+
 namespace Locator {
 namespace Internal {
 
@@ -622,6 +624,5 @@ void LocatorWidget::showEvent(QShowEvent *event)
 
 void LocatorWidget::showConfigureDialog()
 {
-    Core::ICore::showOptionsDialog(QLatin1String(Core::Constants::SETTINGS_CATEGORY_CORE),
-          QLatin1String(Constants::FILTER_OPTIONS_PAGE));
+    ICore::showOptionsDialog(Core::Constants::SETTINGS_CATEGORY_CORE, Constants::FILTER_OPTIONS_PAGE);
 }
diff --git a/src/plugins/madde/maemosettingspages.cpp b/src/plugins/madde/maemosettingspages.cpp
index fbcb5291527a7087b7c6357a4853deef62b81111..6fd95571d86e8e901a7505ddf0f66e2a5d0a4031 100644
--- a/src/plugins/madde/maemosettingspages.cpp
+++ b/src/plugins/madde/maemosettingspages.cpp
@@ -92,7 +92,7 @@ private:
     Q_SLOT void showSettingsPage()
     {
         Core::ICore::showOptionsDialog(MaemoQemuSettingsPage::pageCategory(),
-            MaemoQemuSettingsPage::pageId());
+            Core::Id(MaemoQemuSettingsPage::pageId()));
         accept();
     }
 };
@@ -105,7 +105,7 @@ MaemoQemuSettingsPage::MaemoQemuSettingsPage(QObject *parent)
 {
     setId(pageId());
     setDisplayName(tr("MeeGo Qemu Settings"));
-    setCategory(pageCategory());
+    setCategory(pageCategory().toString());
     //setDisplayCategory(QString()); // Will be set by device configurations page.
     //setCategoryIcon(QIcon()) // See above.
 }
@@ -141,9 +141,9 @@ QString MaemoQemuSettingsPage::pageId()
     return QLatin1String("ZZ.Qemu Settings");
 }
 
-QString MaemoQemuSettingsPage::pageCategory()
+Core::Id MaemoQemuSettingsPage::pageCategory()
 {
-    return QLatin1String(ProjectExplorer::Constants::DEVICE_SETTINGS_CATEGORY);
+    return ProjectExplorer::Constants::DEVICE_SETTINGS_CATEGORY;
 }
 
 } // namespace Internal
diff --git a/src/plugins/madde/maemosettingspages.h b/src/plugins/madde/maemosettingspages.h
index b374f1f210bec6b18372288e00d0837af33daca2..a652a96ad920ac4bef80c2ab0dc78057e766e6d6 100644
--- a/src/plugins/madde/maemosettingspages.h
+++ b/src/plugins/madde/maemosettingspages.h
@@ -31,6 +31,7 @@
 #define MAEMOSETTINGSPAGES_H
 
 #include <coreplugin/dialogs/ioptionspage.h>
+#include <coreplugin/id.h>
 
 namespace Madde{
 namespace Internal {
@@ -50,7 +51,7 @@ public:
 
     static void showQemuCrashDialog();
     static QString pageId();
-    static QString pageCategory();
+    static Core::Id pageCategory();
 
 private:
     QString m_keywords;
diff --git a/src/plugins/projectexplorer/kitinformationconfigwidget.cpp b/src/plugins/projectexplorer/kitinformationconfigwidget.cpp
index 03ca32538adf721618bf290124b7024f119d2330..b83d8e835273d91fe225d6b067c0d1a403e663fd 100644
--- a/src/plugins/projectexplorer/kitinformationconfigwidget.cpp
+++ b/src/plugins/projectexplorer/kitinformationconfigwidget.cpp
@@ -46,6 +46,8 @@
 #include <QLabel>
 #include <QPushButton>
 
+using namespace Core;
+
 namespace ProjectExplorer {
 namespace Internal {
 
@@ -186,8 +188,8 @@ void ToolChainInformationConfigWidget::toolChainUpdated(ProjectExplorer::ToolCha
 
 void ToolChainInformationConfigWidget::manageToolChains()
 {
-    Core::ICore::showOptionsDialog(QLatin1String(ProjectExplorer::Constants::PROJECTEXPLORER_SETTINGS_CATEGORY),
-                                   QLatin1String(ProjectExplorer::Constants::TOOLCHAIN_SETTINGS_PAGE_ID));
+    Core::ICore::showOptionsDialog(Constants::PROJECTEXPLORER_SETTINGS_CATEGORY,
+                                   Constants::TOOLCHAIN_SETTINGS_PAGE_ID);
 }
 
 void ToolChainInformationConfigWidget::currentToolChainChanged(int idx)
@@ -333,8 +335,8 @@ QWidget *DeviceInformationConfigWidget::buttonWidget() const
 
 void DeviceInformationConfigWidget::manageDevices()
 {
-    Core::ICore::showOptionsDialog(QLatin1String(ProjectExplorer::Constants::DEVICE_SETTINGS_CATEGORY),
-                                   QLatin1String(ProjectExplorer::Constants::DEVICE_SETTINGS_PAGE_ID));
+    ICore::showOptionsDialog(Constants::DEVICE_SETTINGS_CATEGORY,
+                             Constants::DEVICE_SETTINGS_PAGE_ID);
 }
 
 void DeviceInformationConfigWidget::modelAboutToReset()
diff --git a/src/plugins/projectexplorer/projectwizardpage.cpp b/src/plugins/projectexplorer/projectwizardpage.cpp
index 2f7cbfa369f2b4ff1966d59a57f35512b934e42c..8098abaea2c821ce6363993e543e470b76cfdd49 100644
--- a/src/plugins/projectexplorer/projectwizardpage.cpp
+++ b/src/plugins/projectexplorer/projectwizardpage.cpp
@@ -193,6 +193,6 @@ void ProjectWizardPage::slotProjectChanged(int index)
 
 void ProjectWizardPage::slotManageVcs()
 {
-    Core::ICore::showOptionsDialog(QLatin1String(VcsBase::Constants::VCS_SETTINGS_CATEGORY),
-                            QLatin1String(VcsBase::Constants::VCS_COMMON_SETTINGS_ID));
+    Core::ICore::showOptionsDialog(VcsBase::Constants::VCS_SETTINGS_CATEGORY,
+                                   VcsBase::Constants::VCS_COMMON_SETTINGS_ID);
 }
diff --git a/src/plugins/projectexplorer/targetsettingspanel.cpp b/src/plugins/projectexplorer/targetsettingspanel.cpp
index b38371e2379cb5232c0b18b1fe0604d2c8fb79fb..a1787b56bfe5153ee44009cc08e292b4f07a5522 100644
--- a/src/plugins/projectexplorer/targetsettingspanel.cpp
+++ b/src/plugins/projectexplorer/targetsettingspanel.cpp
@@ -59,9 +59,11 @@
 #include <QVBoxLayout>
 #include <QToolTip>
 
-using namespace ProjectExplorer;
-using namespace ProjectExplorer::Internal;
 
+using namespace Core;
+
+namespace ProjectExplorer {
+namespace Internal {
 
 ///
 // TargetSettingsWidget
@@ -593,13 +595,12 @@ void TargetSettingsPanelWidget::openTargetPreferences()
 {
     int targetIndex = m_selector->currentIndex();
     if (targetIndex >= 0 && targetIndex < m_targets.size()) {
-        ProjectExplorer::KitOptionsPage *page =
-                ExtensionSystem::PluginManager::instance()->getObject<ProjectExplorer::KitOptionsPage>();
+        KitOptionsPage *page = ExtensionSystem::PluginManager::getObject<ProjectExplorer::KitOptionsPage>();
         if (page)
             page->showKit(m_targets.at(targetIndex)->kit());
     }
-    Core::ICore::showOptionsDialog(QLatin1String(Constants::PROJECTEXPLORER_SETTINGS_CATEGORY),
-                                   QLatin1String(Constants::KITS_SETTINGS_PAGE_ID));
+    ICore::showOptionsDialog(Constants::PROJECTEXPLORER_SETTINGS_CATEGORY,
+                             Constants::KITS_SETTINGS_PAGE_ID);
 }
 
 int TargetSettingsPanelWidget::currentSubIndex() const
@@ -611,3 +612,6 @@ void TargetSettingsPanelWidget::setCurrentSubIndex(int subIndex)
 {
     m_selector->setCurrentSubIndex(subIndex);
 }
+
+} // namespace Internal
+} // namespace ProjectExplorer
diff --git a/src/plugins/qmlprojectmanager/qmlprojectplugin.cpp b/src/plugins/qmlprojectmanager/qmlprojectplugin.cpp
index 4d63eeb2ebb9ec89dd11b607f40a45fcf769193c..eb738d1e1d15720641c567e0136d95dafa82d392 100644
--- a/src/plugins/qmlprojectmanager/qmlprojectplugin.cpp
+++ b/src/plugins/qmlprojectmanager/qmlprojectplugin.cpp
@@ -116,8 +116,8 @@ void QmlProjectPlugin::showQmlObserverToolWarning()
     dialog.exec();
     if (dialog.clickedButton() == qtPref) {
         Core::ICore::showOptionsDialog(
-                    QLatin1String(ProjectExplorer::Constants::PROJECTEXPLORER_SETTINGS_CATEGORY),
-                    QLatin1String(QtSupport::Constants::QTVERSION_SETTINGS_PAGE_ID));
+                    ProjectExplorer::Constants::PROJECTEXPLORER_SETTINGS_CATEGORY,
+                    QtSupport::Constants::QTVERSION_SETTINGS_PAGE_ID);
     }
 }
 
diff --git a/src/plugins/qt4projectmanager/qt4targetsetupwidget.cpp b/src/plugins/qt4projectmanager/qt4targetsetupwidget.cpp
index 893b9b6dcfd2198c055930b229a0ec0bb50995cf..de2577ebb0eee1332d72069f12b52692fb50c520 100644
--- a/src/plugins/qt4projectmanager/qt4targetsetupwidget.cpp
+++ b/src/plugins/qt4projectmanager/qt4targetsetupwidget.cpp
@@ -228,8 +228,8 @@ void Qt4TargetSetupWidget::manageKit()
         return;
 
     page->showKit(m_kit);
-    Core::ICore::showOptionsDialog(QLatin1String(ProjectExplorer::Constants::PROJECTEXPLORER_SETTINGS_CATEGORY),
-                                   QLatin1String(ProjectExplorer::Constants::KITS_SETTINGS_PAGE_ID));
+    Core::ICore::showOptionsDialog(ProjectExplorer::Constants::PROJECTEXPLORER_SETTINGS_CATEGORY,
+                                   ProjectExplorer::Constants::KITS_SETTINGS_PAGE_ID);
 }
 
 void Qt4TargetSetupWidget::setProFilePath(const QString &proFilePath)
diff --git a/src/plugins/qt4projectmanager/wizards/targetsetuppage.cpp b/src/plugins/qt4projectmanager/wizards/targetsetuppage.cpp
index d5b61dc344cdbbad61b65c2e7bd59b1f5c06bcee..bb4923202318775c89fc362b8918a80b02193eca 100644
--- a/src/plugins/qt4projectmanager/wizards/targetsetuppage.cpp
+++ b/src/plugins/qt4projectmanager/wizards/targetsetuppage.cpp
@@ -625,8 +625,8 @@ void TargetSetupPage::updateVisibility()
 
 void TargetSetupPage::openOptions()
 {
-    Core::ICore::instance()->showOptionsDialog(QLatin1String(ProjectExplorer::Constants::PROJECTEXPLORER_SETTINGS_CATEGORY),
-                                               QLatin1String(ProjectExplorer::Constants::KITS_SETTINGS_PAGE_ID),
+    Core::ICore::instance()->showOptionsDialog(ProjectExplorer::Constants::PROJECTEXPLORER_SETTINGS_CATEGORY,
+                                               ProjectExplorer::Constants::KITS_SETTINGS_PAGE_ID,
                                                this);
 }
 
diff --git a/src/plugins/qtsupport/qtkitconfigwidget.cpp b/src/plugins/qtsupport/qtkitconfigwidget.cpp
index c5a3fb033a0ee8e71d53e7b384f56800baef921d..fcec616cc29482fb0a6c07c51fe7c207d9d14a8a 100644
--- a/src/plugins/qtsupport/qtkitconfigwidget.cpp
+++ b/src/plugins/qtsupport/qtkitconfigwidget.cpp
@@ -128,8 +128,8 @@ void QtKitConfigWidget::versionsChanged(const QList<int> &added, const QList<int
 
 void QtKitConfigWidget::manageQtVersions()
 {
-    Core::ICore::showOptionsDialog(QLatin1String(ProjectExplorer::Constants::PROJECTEXPLORER_SETTINGS_CATEGORY),
-                                   QLatin1String(QtSupport::Constants::QTVERSION_SETTINGS_PAGE_ID));
+    Core::ICore::showOptionsDialog(ProjectExplorer::Constants::PROJECTEXPLORER_SETTINGS_CATEGORY,
+                                   Constants::QTVERSION_SETTINGS_PAGE_ID);
 }
 
 void QtKitConfigWidget::currentWasChanged(int idx)
diff --git a/src/plugins/texteditor/plaintexteditor.cpp b/src/plugins/texteditor/plaintexteditor.cpp
index 84b03254cb1ae1df9f62421f2d813ae6d76706cb..7a0eb2499691087d900bab98abbf16be71c9786c 100644
--- a/src/plugins/texteditor/plaintexteditor.cpp
+++ b/src/plugins/texteditor/plaintexteditor.cpp
@@ -51,9 +51,11 @@
 
 #include <QDebug>
 
-using namespace TextEditor;
+using namespace Core;
 using namespace TextEditor::Internal;
 
+namespace TextEditor {
+
 PlainTextEditor::PlainTextEditor(PlainTextEditorWidget *editor)
   : BaseTextEditor(editor)
 {
@@ -218,11 +220,13 @@ QString PlainTextEditorWidget::findDefinitionId(const Core::MimeType &mimeType,
 
 void PlainTextEditorWidget::acceptMissingSyntaxDefinitionInfo()
 {
-    Core::ICore::showOptionsDialog(QLatin1String(Constants::TEXT_EDITOR_SETTINGS_CATEGORY),
-                                               QLatin1String(Constants::TEXT_EDITOR_HIGHLIGHTER_SETTINGS));
+    ICore::showOptionsDialog(Constants::TEXT_EDITOR_SETTINGS_CATEGORY,
+                             Constants::TEXT_EDITOR_HIGHLIGHTER_SETTINGS);
 }
 
 void PlainTextEditorWidget::ignoreMissingSyntaxDefinitionInfo()
 {
     m_ignoreMissingSyntaxDefinition = true;
 }
+
+} // namespace TextEditor
diff --git a/src/plugins/vcsbase/vcsconfigurationpage.cpp b/src/plugins/vcsbase/vcsconfigurationpage.cpp
index 9d40e0e701a4a252d329751b50562a0ec9e60ace..775eb7cbf899e5913a238cb6962ce9b9b54a377e 100644
--- a/src/plugins/vcsbase/vcsconfigurationpage.cpp
+++ b/src/plugins/vcsbase/vcsconfigurationpage.cpp
@@ -83,8 +83,8 @@ bool VcsConfigurationPage::isComplete() const
 
 void VcsConfigurationPage::openConfiguration()
 {
-    Core::ICore::showOptionsDialog(QLatin1String(VcsBase::Constants::VCS_SETTINGS_CATEGORY),
-                                   d->m_versionControl->id().toString());
+    Core::ICore::showOptionsDialog(Constants::VCS_SETTINGS_CATEGORY,
+                                   d->m_versionControl->id());
 }
 
 } // namespace VcsBase