diff --git a/orx-jvm/orx-gui/src/demo/kotlin/DemoAppearance01.kt b/orx-jvm/orx-gui/src/demo/kotlin/DemoAppearance01.kt
index ae6b3193..a083f955 100644
--- a/orx-jvm/orx-gui/src/demo/kotlin/DemoAppearance01.kt
+++ b/orx-jvm/orx-gui/src/demo/kotlin/DemoAppearance01.kt
@@ -19,10 +19,9 @@ fun main() = application {
             }
         }
 
-        val gui = GUI(GUIAppearance(barWidth = 400))
+        val gui = GUI(GUIAppearance(baseColor = ColorRGBa.GRAY.opacify(0.9), barWidth = 400))
         gui.compartmentsCollapsedByDefault = false
 
-
         val settings = @Description("Settings") object {
             @DoubleParameter("radius", 0.0, 100.0)
             var radius = 50.0
diff --git a/orx-jvm/orx-gui/src/demo/kotlin/DemoMultiWindow01.kt b/orx-jvm/orx-gui/src/demo/kotlin/DemoMultiWindow01.kt
new file mode 100644
index 00000000..9a52c09b
--- /dev/null
+++ b/orx-jvm/orx-gui/src/demo/kotlin/DemoMultiWindow01.kt
@@ -0,0 +1,32 @@
+import org.openrndr.WindowConfiguration
+import org.openrndr.application
+import org.openrndr.extra.gui.GUI
+import org.openrndr.extra.parameters.*
+import org.openrndr.window
+import kotlin.system.exitProcess
+
+/**
+ * Demonstration of multi window GUI in the manual way
+ */
+fun main() {
+    // skip this demo on CI
+    if (System.getProperty("takeScreenshot") == "true") {
+        exitProcess(0)
+    }
+    application {
+        program {
+            val settings = object  {
+                @DoubleParameter("radius", 10.0, 100.0)
+                var radius = 10.0
+            }
+            window(WindowConfiguration(width = 200, resizable = true)) {
+                val gui = GUI()
+                gui.add(settings)
+                extend(gui)
+            }
+            extend {
+                drawer.circle(drawer.bounds.center, settings.radius)
+            }
+        }
+    }
+}
\ No newline at end of file
diff --git a/orx-jvm/orx-gui/src/demo/kotlin/DemoMultiWindow02.kt b/orx-jvm/orx-gui/src/demo/kotlin/DemoMultiWindow02.kt
new file mode 100644
index 00000000..162f49bc
--- /dev/null
+++ b/orx-jvm/orx-gui/src/demo/kotlin/DemoMultiWindow02.kt
@@ -0,0 +1,32 @@
+import org.openrndr.WindowConfiguration
+import org.openrndr.application
+import org.openrndr.extra.gui.GUI
+import org.openrndr.extra.gui.WindowedGUI
+import org.openrndr.extra.parameters.*
+import org.openrndr.window
+import kotlin.system.exitProcess
+
+/**
+ * Demonstration of multi window GUI using WindowedGUI extension
+ */
+fun main() {
+    // skip this demo on CI
+    if (System.getProperty("takeScreenshot") == "true") {
+        exitProcess(0)
+    }
+    application {
+        program {
+            val settings = object {
+                @DoubleParameter("radius", 10.0, 100.0)
+                var radius = 10.0
+            }
+            val gui = WindowedGUI()
+            gui.add(settings)
+            extend(gui)
+
+            extend {
+                drawer.circle(drawer.bounds.center, settings.radius)
+            }
+        }
+    }
+}
\ No newline at end of file
diff --git a/orx-jvm/orx-gui/src/main/kotlin/Gui.kt b/orx-jvm/orx-gui/src/main/kotlin/Gui.kt
index 301237bf..6e00330b 100644
--- a/orx-jvm/orx-gui/src/main/kotlin/Gui.kt
+++ b/orx-jvm/orx-gui/src/main/kotlin/Gui.kt
@@ -48,6 +48,10 @@ private class TrackedObjectBinding(
 private val persistentCompartmentStates = mutableMapOf<Long, MutableMap<String, CompartmentState>>()
 private val persistentSidebarStates = mutableMapOf<Long, SidebarState>()
 
+private fun compartmentState(): MutableMap<String, CompartmentState> = persistentCompartmentStates.getOrPut(Driver.instance.contextID) {
+    mutableMapOf()
+}
+
 private fun sidebarState(): SidebarState = persistentSidebarStates.getOrPut(Driver.instance.contextID) {
     SidebarState()
 }
@@ -57,7 +61,7 @@ private fun <T : Any> getPersistedOrDefault(
     property: KMutableProperty1<Any, T>,
     obj: Any
 ): T {
-    val state = persistentCompartmentStates[Driver.instance.contextID]!![compartmentLabel]
+    val state = compartmentState()[compartmentLabel]
     if (state == null) {
         return property.get(obj)
     } else {
@@ -68,17 +72,19 @@ private fun <T : Any> getPersistedOrDefault(
 
 private fun <T : Any> setAndPersist(compartmentLabel: String, property: KMutableProperty1<Any, T>, obj: Any, value: T) {
     property.set(obj, value)
-    val state = persistentCompartmentStates[Driver.instance.contextID]!![compartmentLabel]!!
+    val state = compartmentState()[compartmentLabel] ?: error("item '$compartmentLabel' not in state (${compartmentState()}. ContextID ${Driver.instance.contextID} )")
     state.parameterValues[property.name] = value
 }
 
 private val logger = KotlinLogging.logger { }
 
 
-class GUIAppearance(val baseColor: ColorRGBa = ColorRGBa.GRAY, val barWidth: Int = 200)
+class GUIAppearance(
+    val baseColor: ColorRGBa = ColorRGBa.GRAY.opacify(0.99),
+    val barWidth: Int = 200)
 
 @Suppress("unused", "UNCHECKED_CAST")
-class GUI(
+open class GUI(
     val appearance: GUIAppearance = GUIAppearance(),
     val defaultStyles: List<StyleSheet> = defaultStyles(),
 ) : Extension {
@@ -204,7 +210,7 @@ class GUI(
                 this.width = 100.percent
                 this.display = Display.FLEX
                 this.flexDirection = FlexDirection.Row
-                this.background = Color.RGBa(appearance.baseColor.copy(alpha = 0.99))
+                this.background = Color.RGBa(appearance.baseColor)
             }
 
             styleSheet(has class_ "collapsed") {
@@ -223,7 +229,7 @@ class GUI(
                 this.paddingRight = 10.px
                 this.marginRight = 2.px
                 this.height = 100.percent
-                this.background = Color.RGBa(appearance.baseColor.copy(alpha = 0.99))
+                this.background = Color.RGBa(appearance.baseColor)
                 this.overflow = Overflow.Scroll
 
                 //<editor-fold desc="1) setup control style">
@@ -360,7 +366,7 @@ class GUI(
                                 val collapseClass = ElementClass("collapsed")
 
                                 /* this is guaranteed to be in the dictionary after insertion through add() */
-                                val collapseState = persistentCompartmentStates[Driver.instance.contextID]!![label]!!
+                                val collapseState = compartmentState()[label]!!
                                 if (collapseState.collapsed) {
                                     collapsible.classes.add(collapseClass)
                                 }
@@ -372,7 +378,7 @@ class GUI(
 
                                     if (KeyModifier.CTRL in me.modifiers) {
                                         collapsible.classes.remove(collapseClass)
-                                        persistentCompartmentStates[Driver.instance.contextID]!!.forEach {
+                                        compartmentState().forEach {
                                             it.value.collapsed = true
                                         }
                                         collapseState.collapsed = false
diff --git a/orx-jvm/orx-gui/src/main/kotlin/WindowedGUI.kt b/orx-jvm/orx-gui/src/main/kotlin/WindowedGUI.kt
new file mode 100644
index 00000000..ef4b233b
--- /dev/null
+++ b/orx-jvm/orx-gui/src/main/kotlin/WindowedGUI.kt
@@ -0,0 +1,31 @@
+package org.openrndr.extra.gui
+
+import org.openrndr.Extension
+import org.openrndr.Program
+import org.openrndr.WindowConfiguration
+import org.openrndr.extra.parameters.title
+import org.openrndr.math.IntVector2
+import org.openrndr.panel.style.StyleSheet
+import org.openrndr.panel.style.defaultStyles
+import org.openrndr.window
+
+class WindowedGUI(val appearance: GUIAppearance = GUIAppearance(), val defaultStyles: List<StyleSheet> = defaultStyles()) : Extension {
+    override var enabled: Boolean = true
+
+    val addedObjects = mutableListOf<Pair<Any, String?>>()
+    fun <T : Any> add(objectWithParameters: T, label: String? = objectWithParameters.title()): T {
+        addedObjects.add(Pair(objectWithParameters, label))
+        return objectWithParameters
+    }
+
+
+    override fun setup(program: Program) {
+        program.window(WindowConfiguration(width = 200, height = program.height, position = program.window.position.toInt() - IntVector2(200,0) )) {
+            val gui = GUI(appearance, defaultStyles)
+            for ((obj, label) in addedObjects) {
+                gui.add(obj, label)
+            }
+            extend(gui)
+        }
+    }
+}
\ No newline at end of file