diff --git a/src/ControlManager.cpp b/src/ControlManager.cpp
index ca6abe3..f7dee83 100644
--- a/src/ControlManager.cpp
+++ b/src/ControlManager.cpp
@@ -1398,7 +1398,8 @@ void Control::keyboardCalback(GLFWwindow* w, int key, int, int action, int mods)
 {
     if (UserInterface::manager().keyboardAvailable())
     {
-        if ( !mods ) {
+        // keys without modifiers in any windows
+        if (!mods) {
             int _key = layoutKey(key);
             Control::manager().input_access_.lock();
             if (_key >= GLFW_KEY_A && _key <= GLFW_KEY_Z) {
@@ -1411,14 +1412,31 @@ void Control::keyboardCalback(GLFWwindow* w, int key, int, int action, int mods)
             }
             Control::manager().input_access_.unlock();
         }
-#if defined(APPLE)
-        else if ( w != Rendering::manager().mainWindow().window() &&
-                 key == GLFW_KEY_F && action == GLFW_PRESS && mods == GLFW_MOD_SUPER  )
-#else
-        else if ( key == GLFW_KEY_F && action == GLFW_PRESS && mods == GLFW_MOD_CONTROL  )
-#endif
+        // keys with modifiers in non-main window
+        else if ( w != Rendering::manager().mainWindow().window() )
         {
-            Rendering::manager().window(w)->toggleFullscreen();
+#if defined(APPLE)
+            if ( key == GLFW_KEY_F && action == GLFW_PRESS && mods == GLFW_MOD_SUPER  )
+#else
+            if ( key == GLFW_KEY_F && action == GLFW_PRESS && mods == GLFW_MOD_CONTROL  )
+#endif
+            {
+                // toggle fullscreen on CTRL+F
+                Rendering::manager().window(w)->toggleFullscreen();
+            }
+#if defined(APPLE)
+            else if ( key == GLFW_KEY_Q && action == GLFW_PRESS && mods == GLFW_MOD_SUPER  )
+#else
+            else if ( key == GLFW_KEY_Q && action == GLFW_PRESS && mods == GLFW_MOD_CONTROL  )
+#endif
+            {
+                // Quit on CTRL+Q (if no main window)
+                if (glfwGetWindowAttrib(Rendering::manager().mainWindow().window(), GLFW_VISIBLE)
+                    == GL_FALSE) {
+                    // close rendering manager = quit
+                    Rendering::manager().close();
+                }
+            }
         }
     }
 }
diff --git a/src/RenderingManager.cpp b/src/RenderingManager.cpp
index fd97f00..53498ea 100644
--- a/src/RenderingManager.cpp
+++ b/src/RenderingManager.cpp
@@ -201,13 +201,24 @@ static void OutputWindowEvent( GLFWwindow *w, int button, int action, int)
 
 static void WindowCloseCallback( GLFWwindow* w )
 {
+    // close main window
     if (Rendering::manager().mainWindow().window() == w) {
         if (!UserInterface::manager().TryClose())
             glfwSetWindowShouldClose(w, GLFW_FALSE);
     }
-    else if (!glfwWindowShouldClose(w)) {
-        Mixer::manager().setView(View::DISPLAYS);
-        Rendering::manager().mainWindow().show();
+    // not main window
+    else {
+        // if headless (main window not visile)
+        if (glfwGetWindowAttrib(Rendering::manager().mainWindow().window(), GLFW_VISIBLE)
+            == GL_FALSE) {
+            // close rendering manager = quit
+            Rendering::manager().close();
+        }
+        // attempt to close shows display view
+        else {
+            Mixer::manager().setView(View::DISPLAYS);
+            Rendering::manager().mainWindow().show();
+        }
     }
 }
 
@@ -397,7 +408,7 @@ bool Rendering::init()
     unsigned int err = 0;
 
     while((err = glGetError()) != GL_NO_ERROR){
-        fprintf(stderr, "394  error %d \n",  err );
+        fprintf(stderr, "GLFW  error %d \n",  err );
     }
 
     //
@@ -444,14 +455,15 @@ RenderingWindow* Rendering::window(int index)
 }
 
 
-void Rendering::show()
+void Rendering::show(bool show_main_window)
 {
     // show output windows
     for (auto it = outputs_.begin(); it != outputs_.end(); ++it)
         it->show();
 
     // show main window
-    main_.show();
+    if (show_main_window || Settings::application.num_output_windows < 1 )
+        main_.show();
 
     // show menu on first show
     UserInterface::manager().showPannel(NAV_MENU);
diff --git a/src/RenderingManager.h b/src/RenderingManager.h
index 6ebd4b5..8832a68 100644
--- a/src/RenderingManager.h
+++ b/src/RenderingManager.h
@@ -116,7 +116,7 @@ public:
     // Initialization OpenGL and GLFW window creation
     bool init();
     // show windows and reset views
-    void show();
+    void show(bool show_main_window = true);
     // true if active rendering window
     bool isActive();
     // draw one frame
diff --git a/src/main.cpp b/src/main.cpp
index 97904c7..bc4c847 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -68,6 +68,7 @@ int main(int argc, char *argv[])
     int versionRequested = 0;
     int testRequested = 0;
     int cleanRequested = 0;
+    int headlessRequested = 0;
     int helpRequested = 0;
     int fontsizeRequested = 0;
     int ret = -1;
@@ -79,6 +80,8 @@ int main(int argc, char *argv[])
             testRequested = 1;
         } else if (strcmp(argv[i], "--clean") == 0 || strcmp(argv[i], "-C") == 0) {
             cleanRequested = 1;
+        } else if (strcmp(argv[i], "--headless") == 0 || strcmp(argv[i], "-L") == 0) {
+            headlessRequested = 1;
         } else if (strcmp(argv[i], "--help") == 0 || strcmp(argv[i], "-H") == 0) {
             helpRequested = 1;
         } else if (strcmp(argv[i], "--fontsize") == 0 || strcmp(argv[i], "-F") == 0) {
@@ -132,12 +135,13 @@ int main(int argc, char *argv[])
     }
 
     if (helpRequested) {
-        printf("Usage: %s [-H, --help] [-V, --version] [-F N, --fontsize N] [-T, --test] [-C, --clean] [filename]\n",
+        printf("Usage: %s [-H, --help] [-V, --version] [-F N, --fontsize N] [-L, --headless] [-T, --test] [-C, --clean] [filename]\n",
                argv[0]);
         printf("Options:\n");
         printf("  --help       : Display usage information\n");
         printf("  --version    : Display version information\n");
         printf("  --fontsize N : Force rendering font size to specified value N\n");
+        printf("  --headless   : Run without GUI\n");
         printf("  --test       : Run rendering test\n");
         printf("  --clean      : Reset user settings\n");
         ret = 0;ret = 0;
@@ -211,7 +215,7 @@ int main(int argc, char *argv[])
 
     // show all windows
     Rendering::manager().draw();
-    Rendering::manager().show();
+    Rendering::manager().show(!headlessRequested);
 
     // try to load file given in argument
     Mixer::manager().load(_openfile);