Index: qthelp/qthelp_config_shared.h
===================================================================
--- qthelp/qthelp_config_shared.h
+++ qthelp/qthelp_config_shared.h
@@ -28,13 +28,17 @@
                       QStringList& pathList,
                       QStringList& ghnsList,
                       QString& searchDir,
-                      bool& loadQtDoc);
+                      bool& loadQtDoc,
+                      bool& extViewer
+                     );
 
 void qtHelpWriteConfig(const QStringList& iconList,
                        const QStringList& nameList,
                        const QStringList& pathList,
                        const QStringList& ghnsList,
                        const QString& searchDir,
-                       const bool loadQtDoc);
+                       const bool loadQtDoc,
+                       const bool extViewer
+                      );
 
 #endif // QTHELP_CONFIG_SHARED_H
Index: qthelp/qthelp_config_shared.cpp
===================================================================
--- qthelp/qthelp_config_shared.cpp
+++ qthelp/qthelp_config_shared.cpp
@@ -25,7 +25,7 @@
 
 void qtHelpReadConfig(QStringList& iconList, QStringList& nameList,
                       QStringList& pathList, QStringList& ghnsList,
-                      QString& searchDir, bool& loadQtDoc)
+                      QString& searchDir, bool& loadQtDoc, bool& extViewer)
 {
     KConfigGroup cg(KSharedConfig::openConfig(), "QtHelp Documentation");
     iconList = cg.readEntry("iconList", QStringList());
@@ -34,11 +34,12 @@
     ghnsList = cg.readEntry("ghnsList", QStringList());
     searchDir = cg.readEntry("searchDir", QString());
     loadQtDoc = cg.readEntry("loadQtDocs", true);
+    extViewer = cg.readEntry("useExternalViewer", false);
 }
 
 void qtHelpWriteConfig(const QStringList& iconList, const QStringList& nameList,
                        const QStringList& pathList, const QStringList& ghnsList,
-                       const QString& searchDir, const bool loadQtDoc)
+                       const QString& searchDir, const bool loadQtDoc, const bool extViewer)
 {
     KConfigGroup cg(KSharedConfig::openConfig(), "QtHelp Documentation");
     cg.writeEntry("iconList", iconList);
@@ -47,4 +48,5 @@
     cg.writeEntry("ghnsList", ghnsList);
     cg.writeEntry("searchDir", searchDir);
     cg.writeEntry("loadQtDocs", loadQtDoc);
+    cg.writeEntry("useExternalViewer", extViewer);
 }
Index: qthelp/qthelpconfig.cpp
===================================================================
--- qthelp/qthelpconfig.cpp
+++ qthelp/qthelpconfig.cpp
@@ -121,6 +121,10 @@
     m_configWidget->qchSearchDir->setMode(KFile::Directory);
     connect(m_configWidget->qchSearchDir, &KUrlRequester::textChanged,
             this, &QtHelpConfig::changed);
+    connect(m_configWidget->externalViewerCheckBox, &QCheckBox::toggled,
+            this, static_cast<void(QtHelpConfig::*)()>(&QtHelpConfig::changed));
+    m_configWidget->externalViewerCheckBox->setToolTip(i18n("Use Qt's Assistant as an external viewer,\n"
+        "called through a script or symlink \"kdevelop-qthelp-viewer\""));
 
     // Set availability information for QtHelp
     m_configWidget->messageAvailabilityQtDocs->setCloseButtonVisible(false);
@@ -130,6 +134,7 @@
         m_configWidget->messageAvailabilityQtDocs->setText(
             i18n("The command \"qmake -query\" could not provide a path to a QtHelp file (QCH)."));
         m_configWidget->loadQtDocsCheckBox->setVisible(false);
+        m_configWidget->externalViewerCheckBox->setVisible(false);
     }
     reset();
 }
@@ -156,8 +161,9 @@
     }
     QString searchDir = m_configWidget->qchSearchDir->text();
     bool loadQtDoc = m_configWidget->loadQtDocsCheckBox->isChecked();
+    bool extViewer = m_configWidget->externalViewerCheckBox->isChecked();
 
-    qtHelpWriteConfig(iconList, nameList, pathList, ghnsList, searchDir, loadQtDoc);
+    qtHelpWriteConfig(iconList, nameList, pathList, ghnsList, searchDir, loadQtDoc, extViewer);
     static_cast<QtHelpPlugin*>(plugin())->readConfig();
 }
 
@@ -167,8 +173,8 @@
 
     QStringList iconList, nameList, pathList, ghnsList;
     QString searchDir;
-    bool loadQtDoc;
-    qtHelpReadConfig(iconList, nameList, pathList, ghnsList, searchDir, loadQtDoc);
+    bool loadQtDoc, extViewer;
+    qtHelpReadConfig(iconList, nameList, pathList, ghnsList, searchDir, loadQtDoc, extViewer);
 
     const int size = qMin(qMin(iconList.size(), nameList.size()), pathList.size());
     for(int i = 0; i < size; ++i) {
@@ -177,6 +183,7 @@
     }
     m_configWidget->qchSearchDir->setText(searchDir);
     m_configWidget->loadQtDocsCheckBox->setChecked(loadQtDoc);
+    m_configWidget->externalViewerCheckBox->setChecked(extViewer);
 
     emit changed();
 }
Index: qthelp/qthelpconfig.ui
===================================================================
--- qthelp/qthelpconfig.ui
+++ qthelp/qthelpconfig.ui
@@ -14,7 +14,16 @@
    <locale language="English" country="UnitedStates"/>
   </property>
   <layout class="QVBoxLayout" name="verticalLayout_2">
-   <property name="margin">
+   <property name="leftMargin">
+    <number>0</number>
+   </property>
+   <property name="topMargin">
+    <number>0</number>
+   </property>
+   <property name="rightMargin">
+    <number>0</number>
+   </property>
+   <property name="bottomMargin">
     <number>0</number>
    </property>
    <item>
@@ -48,10 +57,10 @@
        </widget>
       </item>
       <item row="1" column="1">
-       <widget class="KUrlRequester" name="qchSearchDir" native="true"/>
+       <widget class="KUrlRequester" name="qchSearchDir"/>
       </item>
       <item row="2" column="0" colspan="2">
-       <widget class="KMessageWidget" name="messageAvailabilityQtDocs" native="true">
+       <widget class="KMessageWidget" name="messageAvailabilityQtDocs">
         <property name="enabled">
          <bool>true</bool>
         </property>
@@ -61,7 +70,7 @@
           <height>0</height>
          </size>
         </property>
-        <property name="text" stdset="0">
+        <property name="text">
          <string/>
         </property>
        </widget>
@@ -171,6 +180,29 @@
     </widget>
    </item>
    <item>
+    <widget class="QGroupBox" name="boxAutoLoad2">
+     <layout class="QFormLayout" name="formLayout2">
+      <item row="0" column="0">
+       <widget class="QLabel" name="labelExternalViewer">
+        <property name="text">
+         <string>&amp;Use external viewer:</string>
+        </property>
+        <property name="buddy">
+         <cstring>externalViewerCheckBox</cstring>
+        </property>
+       </widget>
+      </item>
+      <item row="0" column="1">
+       <widget class="QCheckBox" name="externalViewerCheckBox">
+        <property name="text">
+         <string/>
+        </property>
+       </widget>
+      </item>
+     </layout>
+    </widget>
+   </item>
+   <item>
     <spacer name="verticalSpacer">
      <property name="orientation">
       <enum>Qt::Vertical</enum>
@@ -187,16 +219,16 @@
  </widget>
  <customwidgets>
   <customwidget>
-   <class>KMessageWidget</class>
-   <extends>QFrame</extends>
-   <header location="global">kmessagewidget.h</header>
-  </customwidget>
-  <customwidget>
    <class>KUrlRequester</class>
    <extends>QWidget</extends>
-   <header location="global">kurlrequester.h</header>
+   <header>kurlrequester.h</header>
    <container>1</container>
   </customwidget>
+  <customwidget>
+   <class>KMessageWidget</class>
+   <extends>QFrame</extends>
+   <header>kmessagewidget.h</header>
+  </customwidget>
  </customwidgets>
  <resources/>
  <connections/>
Index: qthelp/qthelpplugin.h
===================================================================
--- qthelp/qthelpplugin.h
+++ qthelp/qthelpplugin.h
@@ -42,6 +42,7 @@
         QList<QtHelpProvider*> qtHelpProviderLoaded();
         bool isQtHelpQtDocLoaded() const;
         bool isQtHelpAvailable() const;
+        bool useExternalViewer() const;
 
         int configPages() const override;
         KDevelop::ConfigPage* configPage(int number, QWidget* parent) override;
@@ -59,6 +60,7 @@
         QList<QtHelpProvider*> m_qtHelpProviders;
         QtHelpQtDoc* m_qtDoc;
         bool m_loadSystemQtDoc;
+        bool m_useExternalViewer;
 };
 
 #endif // QTHELPPLUGIN_H
Index: qthelp/qthelpplugin.cpp
===================================================================
--- qthelp/qthelpplugin.cpp
+++ qthelp/qthelpplugin.cpp
@@ -40,6 +40,7 @@
     , m_qtHelpProviders()
     , m_qtDoc(new QtHelpQtDoc(this, QVariantList()))
     , m_loadSystemQtDoc(false)
+    , m_useExternalViewer(false)
 {
     Q_UNUSED(args);
     s_plugin = this;
@@ -56,11 +57,12 @@
 {
     QStringList iconList, nameList, pathList, ghnsList;
     QString searchDir;
-    qtHelpReadConfig(iconList, nameList, pathList, ghnsList, searchDir, m_loadSystemQtDoc);
+    qtHelpReadConfig(iconList, nameList, pathList, ghnsList, searchDir, m_loadSystemQtDoc, m_useExternalViewer);
 
     searchHelpDirectory(pathList, nameList, iconList, searchDir);
     loadQtHelpProvider(pathList, nameList, iconList);
     loadQtDocumentation(m_loadSystemQtDoc);
+    m_qtDoc->setUseExternalViewer(m_useExternalViewer);
 
     emit changedProvidersList();
 }
@@ -160,6 +162,11 @@
     return m_loadSystemQtDoc;
 }
 
+bool QtHelpPlugin::useExternalViewer() const
+{
+    return m_useExternalViewer;
+}
+
 bool QtHelpPlugin::isQtHelpAvailable() const
 {
     return !m_qtDoc->qchFiles().isEmpty();
Index: qthelp/qthelpproviderabstract.h
===================================================================
--- qthelp/qthelpproviderabstract.h
+++ qthelp/qthelpproviderabstract.h
@@ -29,6 +29,8 @@
 #include <QVariantList>
 #include <QHelpEngine>
 
+class ExternalViewerProcess;
+
 class QtHelpProviderAbstract : public QObject, public KDevelop::IDocumentationProvider
 {
     Q_OBJECT
@@ -46,6 +48,10 @@
     /// @return False in case we failed to load any documentation files, else true
     bool isValid() const;
 
+    ExternalViewerProcess *externalViewer() const;
+    template<typename T> bool externalViewerCommand(const T& command) const;
+    void setUseExternalViewer(const bool extViewer);
+
     QHelpEngine* engine() { return &m_engine; }
 public slots:
     void jumpedTo(const QUrl& newUrl) const;
@@ -53,6 +59,9 @@
     void addHistory(const KDevelop::IDocumentation::Ptr& doc) const override;
 protected:
     QHelpEngine m_engine;
+    static bool m_useExternalViewer;
+    static ExternalViewerProcess* m_externalViewerProcess;
+    friend class ExternalViewerProcess;
 };
 
 #endif // QTHELPPROVIDERABSTRACT_H
Index: qthelp/qthelpproviderabstract.cpp
===================================================================
--- qthelp/qthelpproviderabstract.cpp
+++ qthelp/qthelpproviderabstract.cpp
@@ -27,6 +27,10 @@
 
 #include <QStandardPaths>
 
+#include <QString>
+#include <QProcess>
+#include <QApplication>
+
 #include <language/duchain/duchain.h>
 #include <language/duchain/declaration.h>
 #include <language/duchain/duchainlock.h>
@@ -37,6 +41,46 @@
 
 using namespace KDevelop;
 
+// subclass QProcess so we can be our own exit watchdog
+class ExternalViewerProcess : public QProcess
+{
+    Q_OBJECT
+public:
+    ExternalViewerProcess(QObject* parent);
+    ~ExternalViewerProcess()
+    {
+        qint64 pid = processId();
+        if (pid > 0) {
+            QProcess *hup = new QProcess(this);
+            hup->start(QString::fromLatin1("kill -1 %1").arg(pid));
+            hup->waitForFinished(500);
+        }
+        QProcess::waitForFinished(500);
+    }
+public slots:
+    void externalViewerExit(int exitCode, QProcess::ExitStatus exitStatus);
+};
+
+ExternalViewerProcess* QtHelpProviderAbstract::m_externalViewerProcess = Q_NULLPTR;
+bool QtHelpProviderAbstract::m_useExternalViewer = false;
+
+ExternalViewerProcess::ExternalViewerProcess(QObject *parent)
+    : QProcess(parent)
+{
+    connect(this, static_cast<void(ExternalViewerProcess::*)(int, QProcess::ExitStatus)>(&ExternalViewerProcess::finished),
+            &ExternalViewerProcess::externalViewerExit);
+}
+
+void ExternalViewerProcess::externalViewerExit(int exitCode, QProcess::ExitStatus exitStatus)
+{
+    if (this == QtHelpProviderAbstract::m_externalViewerProcess) {
+        qCDebug(QTHELP) << Q_FUNC_INFO << "externalViewer" << this << "has exited with code"
+            << exitCode << "and status" << exitStatus;
+        deleteLater();
+        QtHelpProviderAbstract::m_externalViewerProcess = Q_NULLPTR;
+    }
+}
+
 QtHelpProviderAbstract::QtHelpProviderAbstract(QObject *parent, const QString &collectionFileName, const QVariantList &args)
     : QObject(parent)
     , m_engine(QStandardPaths::writableLocation(QStandardPaths::DataLocation)+'/'+collectionFileName)
@@ -45,13 +89,47 @@
     if( !m_engine.setupData() ) {
         qWarning() << "Couldn't setup QtHelp Collection file";
     }
+    m_useExternalViewer = false;
 }
 
-
 QtHelpProviderAbstract::~QtHelpProviderAbstract()
 {
 }
 
+void QtHelpProviderAbstract::setUseExternalViewer(const bool extViewer)
+{
+    m_useExternalViewer = extViewer;
+}
+
+ExternalViewerProcess* QtHelpProviderAbstract::externalViewer() const
+{
+    // turning off the use of an external help viewer shouldn't terminate
+    // an already running viewer process, we just stop using it.
+    if (!m_useExternalViewer) {
+        return Q_NULLPTR;
+    }
+    if (!m_externalViewerProcess) {
+        m_externalViewerProcess = new ExternalViewerProcess(qApp);
+        QStringList args = {"-enableRemoteControl"};
+        m_externalViewerProcess->start(QStandardPaths::findExecutable(QLatin1String("kdevelop-qthelp-viewer")),
+            args, QIODevice::WriteOnly|QIODevice::Append);
+        if (!m_externalViewerProcess->waitForStarted()) {
+            m_externalViewerProcess->deleteLater();
+            m_externalViewerProcess = NULL;
+        }
+    }
+    return m_externalViewerProcess;
+}
+
+template<typename T> bool QtHelpProviderAbstract::externalViewerCommand(const T& command) const
+{
+    if (externalViewer()) {
+        return externalViewer()->write(command) >= 0;
+    } else {
+        return false;
+    }
+}
+
 IDocumentation::Ptr QtHelpProviderAbstract::documentationForDeclaration(Declaration* dec) const
 {
     QtHelpDocumentation::s_provider = const_cast<QtHelpProviderAbstract*>(this);
@@ -69,8 +147,22 @@
         if (!id.isEmpty()) {
             QMap<QString, QUrl> links = m_engine.linksForIdentifier(id);
 
-            if(!links.isEmpty())
+            if(!links.isEmpty()) {
+                if (externalViewer()) {
+                    QByteArray ba;
+                    QList<QUrl> urls = links.values();
+                    foreach (const auto url, urls) {
+                        if (!url.isEmpty()) {
+                            ba.append(QString::fromLatin1("setSource ") + url.toString() + QLatin1String("\n"));
+                        }
+                    }
+                    qCDebug(QTHELP) << Q_FUNC_INFO << "Id=" << id << "links=" << links << "->" << ba;
+                    externalViewerCommand(ba);
+                    externalViewerCommand("show contents\n");
+                    externalViewerCommand("syncContents\n");
+                }
                 return IDocumentation::Ptr(new QtHelpDocumentation(id, links));
+            }
         }
     }
 
@@ -87,7 +179,21 @@
 {
     QtHelpDocumentation::s_provider = const_cast<QtHelpProviderAbstract*>(this);
     QString name=idx.data(Qt::DisplayRole).toString();
-    return IDocumentation::Ptr(new QtHelpDocumentation(name, m_engine.indexModel()->linksForKeyword(name)));
+    QMap<QString, QUrl> links = m_engine.indexModel()->linksForKeyword(name);
+    if(!links.isEmpty() && externalViewer()) {
+        QByteArray ba;
+        QList<QUrl> urls = links.values();
+        foreach (const auto url, urls) {
+            if (!url.isEmpty()) {
+                ba.append(QString::fromLatin1("setSource ") + url.toString() + QLatin1String("\n"));
+                ba.append(QLatin1String("show contents\n"));
+            }
+        }
+        qCDebug(QTHELP) << Q_FUNC_INFO << "name=" << name << "->" << ba;
+        externalViewerCommand(ba);
+        externalViewerCommand("syncContents\n");
+    }
+    return IDocumentation::Ptr(new QtHelpDocumentation(name, links));
 }
 
 void QtHelpProviderAbstract::jumpedTo(const QUrl& newUrl) const
@@ -109,3 +215,5 @@
 {
     return !m_engine.registeredDocumentations().isEmpty();
 }
+
+#include "qthelpproviderabstract.moc"
Index: qthelp/tests/test_qthelpplugin.cpp
===================================================================
--- qthelp/tests/test_qthelpplugin.cpp
+++ qthelp/tests/test_qthelpplugin.cpp
@@ -58,7 +58,7 @@
 {
     m_plugin = new QtHelpPlugin(m_testCore, QVariantList());
     // write default config and read it
-    qtHelpWriteConfig(QStringList(), QStringList(), QStringList(), QStringList(), QString(), true);
+    qtHelpWriteConfig(QStringList(), QStringList(), QStringList(), QStringList(), QString(), true, false);
     m_plugin->readConfig();
 }
 
@@ -82,7 +82,7 @@
 
 void TestQtHelpPlugin::testUnsetQtHelpDoc()
 {
-    qtHelpWriteConfig(QStringList(), QStringList(), QStringList(), QStringList(), QString(), false);
+    qtHelpWriteConfig(QStringList(), QStringList(), QStringList(), QStringList(), QString(), false, false);
     m_plugin->readConfig();
 
     QCOMPARE(m_plugin->providers().size(), 0);
@@ -95,7 +95,7 @@
     name << "file1";
     icon << "myIcon";
     ghns << "0";
-    qtHelpWriteConfig(icon, name, path, ghns, QString(), true);
+    qtHelpWriteConfig(icon, name, path, ghns, QString(), true, false);
     m_plugin->readConfig();
 
     QCOMPARE(m_plugin->qtHelpProviderLoaded().size(), 1);
@@ -111,7 +111,7 @@
     name << "file1" << "file2";
     icon << "myIcon" << "myIcon";
     ghns << "0" << "0";
-    qtHelpWriteConfig(icon, name, path, ghns, QString(), true);
+    qtHelpWriteConfig(icon, name, path, ghns, QString(), true, false);
     m_plugin->readConfig();
 
     QCOMPARE(m_plugin->qtHelpProviderLoaded().size(), 2);
@@ -132,7 +132,7 @@
     name << "file1";
     icon << "myIcon";
     ghns << "0";
-    qtHelpWriteConfig(icon, name, path, ghns, QString(), true);
+    qtHelpWriteConfig(icon, name, path, ghns, QString(), true, false);
     m_plugin->readConfig();
 
     QCOMPARE(m_plugin->qtHelpProviderLoaded().size(), 0);
@@ -145,7 +145,7 @@
     name << "file1" << "file2";
     icon << "myIcon" << "myIcon";
     ghns << "0" << "0";
-    qtHelpWriteConfig(icon, name, path, ghns, QString(), true);
+    qtHelpWriteConfig(icon, name, path, ghns, QString(), true, false);
     m_plugin->readConfig();
 
     QCOMPARE(m_plugin->qtHelpProviderLoaded().size(), 1);
@@ -158,7 +158,7 @@
     name << "file1" << "file2";
     icon << "myIcon" << "myIcon";
     ghns << "0" << "0";
-    qtHelpWriteConfig(icon, name, path, ghns, QString(), true);
+    qtHelpWriteConfig(icon, name, path, ghns, QString(), true, false);
     m_plugin->readConfig();
 
     QCOMPARE(m_plugin->qtHelpProviderLoaded().size(), 2);
@@ -168,7 +168,7 @@
     name.removeAt(1);
     icon.removeAt(1);
     ghns.removeAt(1);
-    qtHelpWriteConfig(icon, name, path, ghns, QString(), true);
+    qtHelpWriteConfig(icon, name, path, ghns, QString(), true, false);
     m_plugin->readConfig();
 
     QCOMPARE(m_plugin->qtHelpProviderLoaded().size(), 1);