diff --git a/2d/particles/particles.tscn b/2d/particles/particles.tscn
index b5414b81..806201fa 100644
--- a/2d/particles/particles.tscn
+++ b/2d/particles/particles.tscn
@@ -721,3 +721,18 @@ T: Toggle particle trails
 Up/Down arrows: Adjust particle trail length
 G: Toggle glow"
 script = ExtResource("6_5a71v")
+
+[node name="UnsupportedLabel" type="Label" parent="CanvasLayer"]
+process_mode = 3
+visible = false
+self_modulate = Color(1, 1, 1, 0.6)
+anchors_preset = 2
+anchor_top = 1.0
+anchor_bottom = 1.0
+offset_left = 16.0
+offset_top = -65.0
+offset_right = 357.0
+offset_bottom = -16.0
+grow_vertical = 0
+text = "Trails are not supported
+in the Compatibility rendering method."
diff --git a/2d/particles/pause.gd b/2d/particles/pause.gd
index 455798c8..99b65d7f 100644
--- a/2d/particles/pause.gd
+++ b/2d/particles/pause.gd
@@ -1,23 +1,34 @@
 extends Label
 
+var is_compatibility := false
+
+
+func _ready() -> void:
+	if RenderingServer.get_current_rendering_method() == "gl_compatibility":
+		is_compatibility = true
+		text = "Space: Pause/Resume\nG: Toggle glow\n\n\n"
+		get_parent().get_node("UnsupportedLabel").visible = true
+		# Increase glow intensity to compensate for lower dynamic range.
+		get_node("../..").environment.glow_intensity = 4.0
+
 
 func _input(event: InputEvent) -> void:
 	if event.is_action_pressed("toggle_pause"):
 		get_tree().paused = not get_tree().paused
 
-	if event.is_action_pressed("toggle_trails"):
+	if not is_compatibility and event.is_action_pressed("toggle_trails"):
 		# Particles disappear if trail type is changed while paused.
 		# Prevent changing particle type while paused to avoid confusion.
 		for particles in get_tree().get_nodes_in_group("trailable_particles"):
 			particles.trail_enabled = not particles.trail_enabled
 
-	if event.is_action_pressed("increase_trail_length"):
+	if not is_compatibility and event.is_action_pressed("increase_trail_length"):
 		# Particles disappear if trail type is changed while paused.
 		# Prevent changing particle type while paused to avoid confusion.
 		for particles in get_tree().get_nodes_in_group("trailable_particles"):
 			particles.trail_lifetime = clampf(particles.trail_lifetime + 0.05, 0.1, 1.0)
 
-	if event.is_action_pressed("decrease_trail_length"):
+	if not is_compatibility and event.is_action_pressed("decrease_trail_length"):
 		# Particles disappear if trail type is changed while paused.
 		# Prevent changing particle type while paused to avoid confusion.
 		for particles in get_tree().get_nodes_in_group("trailable_particles"):
diff --git a/2d/particles/project.godot b/2d/particles/project.godot
index 04329868..0c2ecf98 100644
--- a/2d/particles/project.godot
+++ b/2d/particles/project.godot
@@ -10,7 +10,7 @@ config_version=5
 
 [application]
 
-config/name="2D GPUParticles3D"
+config/name="2D GPUParticles"
 config/description="This demo showcases how 2D particle systems work in Godot."
 config/tags=PackedStringArray("2d", "demo", "official", "rendering")
 run/main_scene="res://particles.tscn"
diff --git a/2d/polygons_lines/polygons_lines.gd b/2d/polygons_lines/polygons_lines.gd
index f3ad873d..1c32d01a 100644
--- a/2d/polygons_lines/polygons_lines.gd
+++ b/2d/polygons_lines/polygons_lines.gd
@@ -1,5 +1,11 @@
 extends Node2D
 
 
+func _ready() -> void:
+	if RenderingServer.get_current_rendering_method() == "gl_compatibility":
+		$MSAA.visible = false
+		$UnsupportedLabel.visible = true
+
+
 func _on_msaa_option_button_item_selected(index: int) -> void:
 	get_viewport().msaa_2d = index as Viewport.MSAA
diff --git a/2d/polygons_lines/polygons_lines.tscn b/2d/polygons_lines/polygons_lines.tscn
index a92ec5d9..509a3747 100644
--- a/2d/polygons_lines/polygons_lines.tscn
+++ b/2d/polygons_lines/polygons_lines.tscn
@@ -146,10 +146,9 @@ text = "MSAA 2D"
 
 [node name="OptionButton" type="OptionButton" parent="MSAA"]
 layout_mode = 2
-item_count = 4
 selected = 0
+item_count = 4
 popup/item_0/text = "Disabled (Fastest)"
-popup/item_0/id = 0
 popup/item_1/text = "2× (Average)"
 popup/item_1/id = 1
 popup/item_2/text = "4× (Slow)"
@@ -157,4 +156,14 @@ popup/item_2/id = 2
 popup/item_3/text = "8× (Slowest)"
 popup/item_3/id = 3
 
+[node name="UnsupportedLabel" type="Label" parent="."]
+visible = false
+self_modulate = Color(1, 1, 1, 0.6)
+offset_left = 24.0
+offset_top = 24.0
+offset_right = 282.0
+offset_bottom = 47.0
+text = "MSAA 2D is not supported
+in the Compatibility rendering method."
+
 [connection signal="item_selected" from="MSAA/OptionButton" to="." method="_on_msaa_option_button_item_selected"]
diff --git a/3d/antialiasing/anti_aliasing.gd b/3d/antialiasing/anti_aliasing.gd
index c5d9b96c..a868ed81 100644
--- a/3d/antialiasing/anti_aliasing.gd
+++ b/3d/antialiasing/anti_aliasing.gd
@@ -15,7 +15,23 @@ var camera_distance := 2.0
 @onready var camera: Camera3D = $CameraHolder/RotationX/Camera3D
 @onready var fps_label: Label = $FPSLabel
 
+var is_compatibility := false
+
+
 func _ready() -> void:
+	if RenderingServer.get_current_rendering_method() == "gl_compatibility":
+		is_compatibility = true
+		# Hide unsupported features.
+		$Antialiasing/FXAAContainer.visible = false
+		$Antialiasing/TAAContainer.visible = false
+
+		# Darken the light's energy to compensate for sRGB blending (without affecting sky rendering).
+		$DirectionalLight3D.sky_mode = DirectionalLight3D.SKY_MODE_SKY_ONLY
+		var new_light: DirectionalLight3D = $DirectionalLight3D.duplicate()
+		new_light.light_energy = 0.3
+		new_light.sky_mode = DirectionalLight3D.SKY_MODE_LIGHT_ONLY
+		add_child(new_light)
+
 	# Disable V-Sync to uncap framerate on supported platforms. This makes performance comparison
 	# easier on high-end machines that easily reach the monitor's refresh rate.
 	DisplayServer.window_set_vsync_mode(DisplayServer.VSYNC_DISABLED)
@@ -98,9 +114,11 @@ func _on_render_scale_value_changed(value: float) -> void:
 	$Antialiasing/RenderScaleContainer/Value.text = "%d%%" % (value * 100)
 	# Update viewport resolution text.
 	_on_viewport_size_changed()
-	# FSR 1.0 is only effective if render scale is below 100%, so hide the setting if at native resolution or higher.
-	$Antialiasing/FidelityFXFSR.visible = value < 1.0
-	$Antialiasing/FSRSharpness.visible = get_viewport().scaling_3d_mode == Viewport.SCALING_3D_MODE_FSR and value < 1.0
+	if not is_compatibility:
+		# Only show the feature if supported.
+		# FSR 1.0 is only effective if render scale is below 100%, so hide the setting if at native resolution or higher.
+		$Antialiasing/FidelityFXFSR.visible = value < 1.0
+		$Antialiasing/FSRSharpness.visible = get_viewport().scaling_3d_mode == Viewport.SCALING_3D_MODE_FSR and value < 1.0
 
 
 func _on_amd_fidelityfx_fsr1_toggled(button_pressed: bool) -> void:
diff --git a/3d/antialiasing/anti_aliasing.tscn b/3d/antialiasing/anti_aliasing.tscn
index 790deeef..e8cd4fd4 100644
--- a/3d/antialiasing/anti_aliasing.tscn
+++ b/3d/antialiasing/anti_aliasing.tscn
@@ -905,7 +905,6 @@ layout_mode = 2
 selected = 0
 item_count = 4
 popup/item_0/text = "Disabled (Fastest)"
-popup/item_0/id = 0
 popup/item_1/text = "2× (Average)"
 popup/item_1/id = 1
 popup/item_2/text = "4× (Slow)"
@@ -932,7 +931,6 @@ layout_mode = 2
 selected = 0
 item_count = 2
 popup/item_0/text = "Disabled (Fastest)"
-popup/item_0/id = 0
 popup/item_1/text = "Enabled (Fast)"
 popup/item_1/id = 1
 
@@ -955,7 +953,6 @@ layout_mode = 2
 selected = 0
 item_count = 2
 popup/item_0/text = "Disabled (Fastest)"
-popup/item_0/id = 0
 popup/item_1/text = "Enabled (Average)"
 popup/item_1/id = 1
 
@@ -977,7 +974,6 @@ layout_mode = 2
 selected = 0
 item_count = 3
 popup/item_0/text = "Disabled"
-popup/item_0/id = 0
 popup/item_1/text = "Adaptive"
 popup/item_1/id = 1
 popup/item_2/text = "Enabled"
@@ -1058,7 +1054,6 @@ layout_mode = 2
 selected = 3
 item_count = 5
 popup/item_0/text = "No FSR Sharpness"
-popup/item_0/id = 0
 popup/item_1/text = "Low FSR Sharpness"
 popup/item_1/id = 1
 popup/item_2/text = "Medium FSR Sharpness"
diff --git a/3d/csg/csg.gd b/3d/csg/csg.gd
index 73df8d9f..5f0b3982 100644
--- a/3d/csg/csg.gd
+++ b/3d/csg/csg.gd
@@ -14,7 +14,16 @@ var camera_distance := 4.0
 @onready var rotation_x: Node3D = $CameraHolder/RotationX
 @onready var camera: Camera3D = $CameraHolder/RotationX/Camera3D
 
+
 func _ready() -> void:
+	if RenderingServer.get_current_rendering_method() == "gl_compatibility":
+		# Darken the light's energy to compensate for sRGB blending (without affecting sky rendering).
+		$DirectionalLight3D.sky_mode = DirectionalLight3D.SKY_MODE_SKY_ONLY
+		var new_light: DirectionalLight3D = $DirectionalLight3D.duplicate()
+		new_light.light_energy = 0.3
+		new_light.sky_mode = DirectionalLight3D.SKY_MODE_LIGHT_ONLY
+		add_child(new_light)
+
 	camera_holder.transform.basis = Basis.from_euler(Vector3(0, rot_y, 0))
 	rotation_x.transform.basis = Basis.from_euler(Vector3(rot_x, 0, 0))
 	update_gui()
diff --git a/3d/global_illumination/project.godot b/3d/global_illumination/project.godot
index 92a06c9b..ddfe1260 100644
--- a/3d/global_illumination/project.godot
+++ b/3d/global_illumination/project.godot
@@ -84,3 +84,4 @@ lights_and_shadows/directional_shadow/soft_shadow_filter_quality=3
 lights_and_shadows/positional_shadow/soft_shadow_filter_quality=3
 anti_aliasing/quality/screen_space_aa=1
 anti_aliasing/quality/use_debanding=true
+anti_aliasing/quality/msaa_3d.web=2
diff --git a/3d/global_illumination/test.gd b/3d/global_illumination/test.gd
index 4f230146..24559ee3 100644
--- a/3d/global_illumination/test.gd
+++ b/3d/global_illumination/test.gd
@@ -9,15 +9,6 @@ enum GIMode {
 	MAX,  # Maximum value of the enum, used internally.
 }
 
-# Keep this in sync with the GIMode enum (except for MAX).
-const GI_MODE_TEXTS = [
-	"Environment Lighting (Fastest)",
-	"Baked Lightmap All (Fast)",
-	"Baked Lightmap Indirect (Average)",
-	"VoxelGI (Slow)",
-	"SDFGI (Slow)",
-]
-
 enum ReflectionProbeMode {
 	NONE,
 	ONCE,
@@ -25,13 +16,6 @@ enum ReflectionProbeMode {
 	MAX,
 }
 
-# Keep this in sync with the ReflectionProbeMode enum (except for MAX).
-const REFLECTION_PROBE_MODE_TEXTS = [
-	"Disabled - Using environment, VoxelGI or SDFGI reflections (Fast)",
-	"Enabled - \"Once\" Update Mode (Average)",
-	"Enabled - \"Always\" Update Mode (Slow)",
-]
-
 enum SSILMode {
 	NONE,
 	SSAO,
@@ -48,10 +32,31 @@ const SSIL_MODE_TEXTS = [
 	"SSAO + SSIL (Slow)",
 ]
 
+# Keep this in sync with the ReflectionProbeMode enum (except for MAX).
+var reflection_probe_mode_texts: Array[String] = [
+	"Disabled - Using environment, VoxelGI or SDFGI reflections (Fast)",
+	"Enabled - \"Once\" Update Mode (Average)",
+	"Enabled - \"Always\" Update Mode (Slow)",
+]
+
+# Keep this in sync with the GIMode enum (except for MAX).
+var gi_mode_texts: Array[String] = [
+	"Environment Lighting (Fastest)",
+	"Baked Lightmap All (Fast)",
+	"Baked Lightmap Indirect (Average)",
+	"VoxelGI (Slow)",
+	"SDFGI (Slow)",
+]
+
 var gi_mode := GIMode.NONE
 var reflection_probe_mode := ReflectionProbeMode.NONE
 var ssil_mode := SSILMode.NONE
+var is_compatibility := false
 
+# This is replaced further below if using Compatibility to point to a newly created DirectionalLight3D
+# (which does not affect sky rendering).
+@onready var sun: DirectionalLight3D = $Sun
+@onready var lightmap_gi_all_data: LightmapGIData = $LightmapGIAll.light_data
 @onready var environment: Environment = $WorldEnvironment.environment
 @onready var gi_mode_label: Label = $GIMode
 @onready var reflection_probe_mode_label: Label = $ReflectionProbeMode
@@ -59,20 +64,44 @@ var ssil_mode := SSILMode.NONE
 @onready var ssil_mode_label: Label = $SSILMode
 
 # Several copies of the level mesh are required to cycle between different GI modes.
-@onready var zdm2_no_lightmap: Node3D = $Zdm2NoLightmap
 @onready var zdm2_lightmap_all: Node3D = $Zdm2LightmapAll
 @onready var zdm2_lightmap_indirect: Node3D = $Zdm2LightmapIndirect
 
 
 func _ready() -> void:
-	set_gi_mode(gi_mode)
+	if RenderingServer.get_current_rendering_method() == "gl_compatibility":
+		is_compatibility = true
+		# Remove unsupported VoxelGI/SDFGI references from the label.
+		reflection_probe_mode_texts[0] = "Disabled - Using environment reflections (Fast)"
+		set_gi_mode(GIMode.NONE)
+		# Darken lights's energy to compensate for sRGB blending (without affecting sky rendering).
+		# This only applies to lights with shadows enabled.
+		$GrateOmniLight.light_energy = 0.25
+		$GarageOmniLight.light_energy = 0.5
+		sun.sky_mode = DirectionalLight3D.SKY_MODE_SKY_ONLY
+		sun = sun.duplicate()
+		sun.light_energy = 0.15
+		sun.sky_mode = DirectionalLight3D.SKY_MODE_LIGHT_ONLY
+		add_child(sun)
+		$Help.text = """Space: Cycle between GI modes
+R: Cycle between reflection probe modes
+Escape or F10: Toggle mouse capture"""
+	else:
+		set_gi_mode(gi_mode)
+
 	set_reflection_probe_mode(reflection_probe_mode)
 	set_ssil_mode(ssil_mode)
 
 
 func _input(event: InputEvent) -> void:
 	if event.is_action_pressed("cycle_gi_mode"):
-		set_gi_mode(wrapi(gi_mode + 1, 0, GIMode.MAX))
+		if is_compatibility:
+			# Only LightmapGI is supported in Compatibility.
+			# Note that the actual GI mode is the opposite of what's being set here, due to a bug
+			# in the Compatibility rendering method.
+			set_gi_mode(wrapi(gi_mode + 1, 0, GIMode.VOXEL_GI))
+		else:
+			set_gi_mode(wrapi(gi_mode + 1, 0, GIMode.MAX))
 
 	if event.is_action_pressed("cycle_reflection_probe_mode"):
 		set_reflection_probe_mode(wrapi(reflection_probe_mode + 1, 0, ReflectionProbeMode.MAX))
@@ -83,12 +112,15 @@ func _input(event: InputEvent) -> void:
 
 func set_gi_mode(p_gi_mode: GIMode) -> void:
 	gi_mode = p_gi_mode
-	gi_mode_label.text = "Global illumination: %s " % GI_MODE_TEXTS[gi_mode]
+	gi_mode_label.text = "Global illumination: %s " % gi_mode_texts[gi_mode]
 
 	match p_gi_mode:
 		GIMode.NONE:
-			$Zdm2NoLightmap.visible = true
-			$Zdm2LightmapAll.visible = false
+			if is_compatibility:
+				# Work around Compatibility bug where lightmaps are still visible if the LightmapGI node is hidden.
+				$LightmapGIAll.light_data = null
+
+			$Zdm2LightmapAll.visible = true
 			$Zdm2LightmapIndirect.visible = false
 
 			# Halve sky contribution to prevent shaded areas from looking too bright and blue.
@@ -100,15 +132,16 @@ func set_gi_mode(p_gi_mode: GIMode) -> void:
 
 			# There is no difference between Indirect and Disabled when no GI is used.
 			# Pick the default value (which is Indirect).
-			$Sun.light_bake_mode = Light3D.BAKE_DYNAMIC
+			sun.light_bake_mode = Light3D.BAKE_DYNAMIC
 			$GrateOmniLight.light_bake_mode = Light3D.BAKE_DYNAMIC
 			$GarageOmniLight.light_bake_mode = Light3D.BAKE_DYNAMIC
 			$CornerSpotLight.light_bake_mode = Light3D.BAKE_DYNAMIC
+			$Camera/Box.gi_mode = GeometryInstance3D.GI_MODE_DISABLED
 
 		GIMode.LIGHTMAP_GI_ALL:
-			$Zdm2NoLightmap.visible = false
 			$Zdm2LightmapAll.visible = true
 			$Zdm2LightmapIndirect.visible = false
+			$LightmapGIAll.light_data = lightmap_gi_all_data
 
 			# Halve sky contribution to prevent dynamic objects from looking too bright and blue.
 			# (When using lightmaps, this property doesn't affect lightmapped surfaces.)
@@ -119,13 +152,15 @@ func set_gi_mode(p_gi_mode: GIMode) -> void:
 			environment.sdfgi_enabled = false
 
 			# Make lights not affect baked surfaces by setting their bake mode to All.
-			$Sun.light_bake_mode = Light3D.BAKE_STATIC
+
+			sun.light_bake_mode = Light3D.BAKE_STATIC
 			$GrateOmniLight.light_bake_mode = Light3D.BAKE_STATIC
 			$GarageOmniLight.light_bake_mode = Light3D.BAKE_STATIC
 			$CornerSpotLight.light_bake_mode = Light3D.BAKE_STATIC
+			$Camera/Box.gi_mode = GeometryInstance3D.GI_MODE_DYNAMIC
 
 		GIMode.LIGHTMAP_GI_INDIRECT:
-			$Zdm2NoLightmap.visible = false
+			$LightmapGIAll.light_data = lightmap_gi_all_data
 			$Zdm2LightmapAll.visible = false
 			$Zdm2LightmapIndirect.visible = true
 
@@ -137,14 +172,20 @@ func set_gi_mode(p_gi_mode: GIMode) -> void:
 			$VoxelGI.visible = false
 			environment.sdfgi_enabled = false
 
-			$Sun.light_bake_mode = Light3D.BAKE_DYNAMIC
+			sun.light_bake_mode = Light3D.BAKE_DYNAMIC
 			$GrateOmniLight.light_bake_mode = Light3D.BAKE_DYNAMIC
 			$GarageOmniLight.light_bake_mode = Light3D.BAKE_DYNAMIC
 			$CornerSpotLight.light_bake_mode = Light3D.BAKE_DYNAMIC
+			# Mark box as dynamic so it benefits from lightmap probes.
+			# Don't do this in other GI modes to avoid the heavy performance impact that
+			# happens with VoxelGI for dynamic objects.
+			$Camera/Box.gi_mode = GeometryInstance3D.GI_MODE_DYNAMIC
 
 		GIMode.VOXEL_GI:
-			$Zdm2NoLightmap.visible = true
-			$Zdm2LightmapAll.visible = false
+			# Work around bug where VoxelGI is not visible if the LightmapGI node is hidden (with LightmapGIData still present).
+			$LightmapGIAll.light_data = null
+
+			$Zdm2LightmapAll.visible = true
 			$Zdm2LightmapIndirect.visible = false
 
 			environment.ambient_light_sky_contribution = 1.0
@@ -155,14 +196,17 @@ func set_gi_mode(p_gi_mode: GIMode) -> void:
 
 			# Bake mode must be Indirect, not Disabled. Otherwise, GI will
 			# not be visible for those lights.
-			$Sun.light_bake_mode = Light3D.BAKE_DYNAMIC
+			sun.light_bake_mode = Light3D.BAKE_DYNAMIC
 			$GrateOmniLight.light_bake_mode = Light3D.BAKE_DYNAMIC
 			$GarageOmniLight.light_bake_mode = Light3D.BAKE_DYNAMIC
 			$CornerSpotLight.light_bake_mode = Light3D.BAKE_DYNAMIC
+			$Camera/Box.gi_mode = GeometryInstance3D.GI_MODE_DISABLED
 
 		GIMode.SDFGI:
-			$Zdm2NoLightmap.visible = true
-			$Zdm2LightmapAll.visible = false
+			# Work around bug where SDFGI is not visible if the LightmapGI node is hidden (with LightmapGIData still present).
+			$LightmapGIAll.light_data = null
+
+			$Zdm2LightmapAll.visible = true
 			$Zdm2LightmapIndirect.visible = false
 
 			environment.ambient_light_sky_contribution = 1.0
@@ -173,15 +217,16 @@ func set_gi_mode(p_gi_mode: GIMode) -> void:
 
 			# Bake mode must be Indirect, not Disabled. Otherwise, GI will
 			# not be visible for those lights.
-			$Sun.light_bake_mode = Light3D.BAKE_DYNAMIC
+			sun.light_bake_mode = Light3D.BAKE_DYNAMIC
 			$GrateOmniLight.light_bake_mode = Light3D.BAKE_DYNAMIC
 			$GarageOmniLight.light_bake_mode = Light3D.BAKE_DYNAMIC
 			$CornerSpotLight.light_bake_mode = Light3D.BAKE_DYNAMIC
+			$Camera/Box.gi_mode = GeometryInstance3D.GI_MODE_DISABLED
 
 
 func set_reflection_probe_mode(p_reflection_probe_mode: ReflectionProbeMode) -> void:
 	reflection_probe_mode = p_reflection_probe_mode
-	reflection_probe_mode_label.text = "Reflection probe: %s " % REFLECTION_PROBE_MODE_TEXTS[reflection_probe_mode]
+	reflection_probe_mode_label.text = "Reflection probe: %s " % reflection_probe_mode_texts[reflection_probe_mode]
 
 	match p_reflection_probe_mode:
 		ReflectionProbeMode.NONE:
@@ -197,7 +242,12 @@ func set_reflection_probe_mode(p_reflection_probe_mode: ReflectionProbeMode) ->
 
 func set_ssil_mode(p_ssil_mode: SSILMode) -> void:
 	ssil_mode = p_ssil_mode
-	ssil_mode_label.text = "Screen-space lighting effects: %s " % SSIL_MODE_TEXTS[ssil_mode]
+	if is_compatibility:
+		ssil_mode_label.text = "Screen-space lighting effects: Not supported on Compatibility"
+		ssil_mode_label.self_modulate.a = 0.6
+		return
+	else:
+		ssil_mode_label.text = "Screen-space lighting effects: %s " % SSIL_MODE_TEXTS[ssil_mode]
 
 	match p_ssil_mode:
 		SSILMode.NONE:
diff --git a/3d/global_illumination/test.tscn b/3d/global_illumination/test.tscn
index 9e2469c6..baf2073f 100644
--- a/3d/global_illumination/test.tscn
+++ b/3d/global_illumination/test.tscn
@@ -3,9 +3,9 @@
 [ext_resource type="PackedScene" uid="uid://djbrxyh5s8j2o" path="res://zdm2.glb" id="1"]
 [ext_resource type="PackedScene" uid="uid://c2lbhsefub1o5" path="res://cube.glb" id="3"]
 [ext_resource type="VoxelGIData" uid="uid://duykbpl6evu0r" path="res://test_VoxelGIData.res" id="3_1netx"]
-[ext_resource type="LightmapGIData" uid="uid://bqpu20db0gmry" path="res://zdm2_all.lmbake" id="4_7vqwx"]
+[ext_resource type="LightmapGIData" uid="uid://c7ltminhf5o56" path="res://zdm2_all.lmbake" id="4_7vqwx"]
 [ext_resource type="Script" uid="uid://b33gdc1jklq5" path="res://test.gd" id="5"]
-[ext_resource type="LightmapGIData" uid="uid://brs3ywo1ouol0" path="res://zdm2_indirect.lmbake" id="5_14bmd"]
+[ext_resource type="LightmapGIData" uid="uid://xmpb2se1j30h" path="res://zdm2_indirect.lmbake" id="5_14bmd"]
 [ext_resource type="Script" uid="uid://bbfpss6nqbjeu" path="res://camera.gd" id="6"]
 
 [sub_resource type="ProceduralSkyMaterial" id="ProceduralSkyMaterial_30v8t"]
@@ -59,30 +59,28 @@ script = ExtResource("5")
 [node name="WorldEnvironment" type="WorldEnvironment" parent="."]
 environment = SubResource("Environment_bau0c")
 
-[node name="Zdm2NoLightmap" parent="." instance=ExtResource("1")]
-transform = Transform3D(1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 2)
-
 [node name="Zdm2LightmapAll" parent="." instance=ExtResource("1")]
 transform = Transform3D(1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 2)
 visible = false
 
 [node name="Zdm2LightmapIndirect" parent="." instance=ExtResource("1")]
 transform = Transform3D(1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 2)
-visible = false
 
 [node name="VoxelGI" type="VoxelGI" parent="."]
 transform = Transform3D(1, 0, 0, 0, 1, 0, 0, 0, 1, 5, 6, 2.5)
+visible = false
 size = Vector3(78, 37, 60)
 data = ExtResource("3_1netx")
 
 [node name="LightmapGIAll" type="LightmapGI" parent="."]
 visible = false
 quality = 3
+generate_probes_subdiv = 3
 light_data = ExtResource("4_7vqwx")
 
 [node name="LightmapGIIndirect" type="LightmapGI" parent="."]
-visible = false
 quality = 3
+generate_probes_subdiv = 3
 light_data = ExtResource("5_14bmd")
 
 [node name="Sun" type="DirectionalLight3D" parent="."]
@@ -134,6 +132,7 @@ script = ExtResource("6")
 [node name="Box" type="MeshInstance3D" parent="Camera"]
 transform = Transform3D(0.999999, -5.12227e-09, 9.68575e-08, 2.79397e-09, 0.999999, 8.9407e-08, 7.45058e-09, -1.11759e-07, 0.999999, -1.4, -0.999998, -3.99998)
 layers = 2
+gi_mode = 0
 mesh = SubResource("8")
 
 [node name="BlobShadow" type="Decal" parent="Camera/Box"]
@@ -148,6 +147,7 @@ cull_mask = 1048573
 [node name="ReflectiveSphere" type="MeshInstance3D" parent="Camera"]
 transform = Transform3D(-0.997523, -8.41886e-09, -0.0703376, -0.00719589, 0.994753, 0.102052, 0.0699685, 0.102305, -0.992289, 0.16733, -1.22931, -3.81225)
 layers = 2
+gi_mode = 0
 mesh = SubResource("2")
 surface_material_override/0 = SubResource("StandardMaterial3D_7doxp")
 
@@ -195,14 +195,15 @@ theme_override_colors/font_outline_color = Color(0, 0, 0, 1)
 theme_override_constants/outline_size = 4
 text = "Screen-space lighting effects: Disabled (Fast)"
 
-[node name="Label" type="Label" parent="."]
+[node name="Help" type="Label" parent="."]
 anchors_preset = 2
 anchor_top = 1.0
 anchor_bottom = 1.0
 offset_left = 16.0
-offset_top = -120.0
+offset_top = -117.0
 offset_right = 537.0
 offset_bottom = -16.0
+grow_vertical = 0
 theme_override_colors/font_outline_color = Color(0, 0, 0, 1)
 theme_override_constants/outline_size = 4
 text = "Space: Cycle between GI modes
diff --git a/3d/global_illumination/zdm2_all.exr.import b/3d/global_illumination/zdm2_all.exr.import
index ec7a7e98..76de954f 100644
--- a/3d/global_illumination/zdm2_all.exr.import
+++ b/3d/global_illumination/zdm2_all.exr.import
@@ -2,7 +2,7 @@
 
 importer="2d_array_texture"
 type="CompressedTexture2DArray"
-uid="uid://cnetwnfnv5way"
+uid="uid://k0tida8bignh"
 path="res://.godot/imported/zdm2_all.exr-90621151e6c7cdb548fd3797293f06e7.ctexarray"
 metadata={
 "vram_texture": false
@@ -15,7 +15,7 @@ dest_files=["res://.godot/imported/zdm2_all.exr-90621151e6c7cdb548fd3797293f06e7
 
 [params]
 
-compress/mode=0
+compress/mode=3
 compress/high_quality=false
 compress/lossy_quality=0.7
 compress/hdr_compression=1
diff --git a/3d/global_illumination/zdm2_all.lmbake b/3d/global_illumination/zdm2_all.lmbake
index 2fbd7e93..00fd17a6 100644
Binary files a/3d/global_illumination/zdm2_all.lmbake and b/3d/global_illumination/zdm2_all.lmbake differ
diff --git a/3d/global_illumination/zdm2_indirect.exr.import b/3d/global_illumination/zdm2_indirect.exr.import
index 11c28d7e..7572d810 100644
--- a/3d/global_illumination/zdm2_indirect.exr.import
+++ b/3d/global_illumination/zdm2_indirect.exr.import
@@ -2,7 +2,7 @@
 
 importer="2d_array_texture"
 type="CompressedTexture2DArray"
-uid="uid://d26s2indfdskr"
+uid="uid://bykd8ka4a55ny"
 path="res://.godot/imported/zdm2_indirect.exr-1fd4bc76ec648c4d2e6230b7d974087b.ctexarray"
 metadata={
 "vram_texture": false
@@ -15,7 +15,7 @@ dest_files=["res://.godot/imported/zdm2_indirect.exr-1fd4bc76ec648c4d2e6230b7d97
 
 [params]
 
-compress/mode=0
+compress/mode=3
 compress/high_quality=false
 compress/lossy_quality=0.7
 compress/hdr_compression=1
diff --git a/3d/global_illumination/zdm2_indirect.lmbake b/3d/global_illumination/zdm2_indirect.lmbake
index 7393e5d0..478b146f 100644
Binary files a/3d/global_illumination/zdm2_indirect.lmbake and b/3d/global_illumination/zdm2_indirect.lmbake differ
diff --git a/3d/graphics_settings/3d_scene.tscn b/3d/graphics_settings/3d_scene.tscn
index 79a40bf9..427efdbd 100644
--- a/3d/graphics_settings/3d_scene.tscn
+++ b/3d/graphics_settings/3d_scene.tscn
@@ -147,10 +147,10 @@ transform = Transform3D(1, 0, 0, 0, 1, 0, 0, 0, 1, -0.342018, -1.18089, 0.661332
 material = SubResource("FogMaterial_tldur")
 
 [node name="AnimationPlayer" type="AnimationPlayer" parent="."]
-autoplay = "move"
 libraries = {
 "": SubResource("AnimationLibrary_m14lt")
 }
+autoplay = "move"
 
 [node name="SpotLight3D" type="SpotLight3D" parent="."]
 transform = Transform3D(0.0245702, 0.999698, -0.000796034, 0, 0.000796274, 1, 0.999698, -0.0245702, 1.95646e-05, -0.864742, 2.11809, 3.11561)
diff --git a/3d/graphics_settings/control.tscn b/3d/graphics_settings/control.tscn
index a8086892..2fab70a9 100644
--- a/3d/graphics_settings/control.tscn
+++ b/3d/graphics_settings/control.tscn
@@ -138,6 +138,14 @@ theme_override_colors/font_color = Color(0.683425, 0.916893, 1, 1)
 text = "Video Settings"
 horizontal_alignment = 1
 
+[node name="UnsupportedLabel" type="Label" parent="SettingsMenu/ScrollContainer/VBoxContainer"]
+unique_name_in_owner = true
+visible = false
+self_modulate = Color(1, 1, 1, 0.6)
+layout_mode = 2
+text = "Some settings are not supported
+on the Compatibility rendering method."
+
 [node name="GridContainer2" type="GridContainer" parent="SettingsMenu/ScrollContainer/VBoxContainer"]
 layout_mode = 2
 columns = 2
@@ -164,6 +172,7 @@ theme_override_font_sizes/font_size = 16
 text = "Display Filter:"
 
 [node name="FilterOptionButton" type="OptionButton" parent="SettingsMenu/ScrollContainer/VBoxContainer/GridContainer2"]
+unique_name_in_owner = true
 layout_mode = 2
 size_flags_horizontal = 3
 theme_override_font_sizes/font_size = 16
@@ -206,9 +215,9 @@ theme_override_font_sizes/font_size = 16
 selected = 0
 item_count = 3
 popup/item_0/text = "Disabled"
-popup/item_1/text = "Enabled"
+popup/item_1/text = "Enabled (Borderless)"
 popup/item_1/id = 1
-popup/item_2/text = "Exclusive"
+popup/item_2/text = "Enabled (Exclusive)"
 popup/item_2/id = 2
 
 [node name="VsyncLabel" type="Label" parent="SettingsMenu/ScrollContainer/VBoxContainer/GridContainer2"]
diff --git a/3d/graphics_settings/settings.gd b/3d/graphics_settings/settings.gd
index 943506e5..eaab8ab2 100644
--- a/3d/graphics_settings/settings.gd
+++ b/3d/graphics_settings/settings.gd
@@ -20,8 +20,30 @@ var viewport_start_size := Vector2(
 	ProjectSettings.get_setting(&"display/window/size/viewport_height")
 )
 
+var is_compatibility := false
+
 
 func _ready() -> void:
+	if RenderingServer.get_current_rendering_method() == "gl_compatibility":
+		is_compatibility = true
+		%UnsupportedLabel.visible = true
+		mark_as_unsupported(%FilterOptionButton)
+		mark_as_unsupported(%TAAOptionButton)
+		mark_as_unsupported(%FXAAOptionButton)
+		mark_as_unsupported(%SDFGIOptionButton)
+		mark_as_unsupported(%SSAOOptionButton)
+		mark_as_unsupported(%SSReflectionsOptionButton)
+		mark_as_unsupported(%SSILOptionButton)
+		mark_as_unsupported(%VolumetricFogOptionButton)
+		# Darken lights's energy to compensate for sRGB blending (without affecting sky rendering).
+		$Node3D/OmniLight3D.light_energy = 0.5
+		$Node3D/SpotLight3D.light_energy = 0.5
+		$Node3D/DirectionalLight3D.sky_mode = DirectionalLight3D.SKY_MODE_SKY_ONLY
+		var new_light: DirectionalLight3D = $Node3D/DirectionalLight3D.duplicate()
+		new_light.light_energy = 0.35
+		new_light.sky_mode = DirectionalLight3D.SKY_MODE_LIGHT_ONLY
+		$Node3D.add_child(new_light)
+
 	get_viewport().size_changed.connect(update_resolution_label)
 	update_resolution_label()
 
@@ -175,9 +197,15 @@ func _on_shadow_size_option_button_item_selected(index):
 		# Higher resolutions can use a lower bias without suffering from shadow acne.
 		directional_light.shadow_bias = 0.06
 
-		# Disable positional (omni/spot) light shadows entirely to further improve performance.
-		# These often don't contribute as much to a scene compared to directional light shadows.
-		get_viewport().positional_shadow_atlas_size = 0
+
+		if is_compatibility:
+			# Work around bug in Compatibility where setting the positional shadow atlas size to 0 breaks rendering.
+			get_viewport().positional_shadow_atlas_size = 512
+		else:
+			# Disable positional (omni/spot) light shadows entirely to further improve performance.
+			# These often don't contribute as much to a scene compared to directional light shadows.
+			get_viewport().positional_shadow_atlas_size = 0
+
 	if index == 1: # Very Low
 		RenderingServer.directional_shadow_atlas_set_size(1024, true)
 		directional_light.shadow_bias = 0.04
@@ -457,3 +485,9 @@ func update_preset() -> void:
 	%SSReflectionsOptionButton.item_selected.emit(%SSReflectionsOptionButton.selected)
 	%SSILOptionButton.item_selected.emit(%SSILOptionButton.selected)
 	%VolumetricFogOptionButton.item_selected.emit(%VolumetricFogOptionButton.selected)
+
+
+func mark_as_unsupported(button: OptionButton) -> void:
+	button.disabled = true
+	button.add_item("Unsupported")
+	button.select(button.item_count - 1)
diff --git a/3d/material_testers/tester.gd b/3d/material_testers/tester.gd
index 7adae5a1..19e06318 100644
--- a/3d/material_testers/tester.gd
+++ b/3d/material_testers/tester.gd
@@ -27,6 +27,11 @@ var backgrounds: Array[Dictionary] = [
 @onready var camera: Camera3D = $CameraHolder/RotationX/Camera
 
 func _ready() -> void:
+	if RenderingServer.get_current_rendering_method() == "gl_compatibility":
+		# Tweak scene brightness to better match Forward+/Mobile.
+		$WorldEnvironment.environment.tonemap_mode = Environment.TONE_MAPPER_FILMIC
+		$WorldEnvironment.environment.background_energy_multiplier = 2.0
+
 	for background in backgrounds:
 		get_node(^"UI/Background").add_item(background.name)
 
diff --git a/3d/platformer/stage/stage.gd b/3d/platformer/stage/stage.gd
new file mode 100644
index 00000000..d423f838
--- /dev/null
+++ b/3d/platformer/stage/stage.gd
@@ -0,0 +1,14 @@
+extends Node3D
+
+
+func _ready() -> void:
+	if RenderingServer.get_current_rendering_method() == "gl_compatibility":
+		# Use PCF13 shadow filtering to improve quality (Medium maps to PCF5 instead).
+		RenderingServer.directional_soft_shadow_filter_set_quality(RenderingServer.SHADOW_QUALITY_SOFT_HIGH)
+
+		# Darken the light's energy to compensate for sRGB blending (without affecting sky rendering).
+		$DirectionalLight3D.sky_mode = DirectionalLight3D.SKY_MODE_SKY_ONLY
+		var new_light: DirectionalLight3D = $DirectionalLight3D.duplicate()
+		new_light.light_energy = 0.25
+		new_light.sky_mode = DirectionalLight3D.SKY_MODE_LIGHT_ONLY
+		add_child(new_light)
diff --git a/3d/platformer/stage/stage.tscn b/3d/platformer/stage/stage.tscn
index df5e6f69..c599c521 100644
--- a/3d/platformer/stage/stage.tscn
+++ b/3d/platformer/stage/stage.tscn
@@ -1,5 +1,6 @@
-[gd_scene load_steps=7 format=3 uid="uid://dohp772jyjxb7"]
+[gd_scene load_steps=8 format=3 uid="uid://dohp772jyjxb7"]
 
+[ext_resource type="Script" path="res://stage/stage.gd" id="1_re4bd"]
 [ext_resource type="PackedScene" uid="uid://dmlvwah3ypol0" path="res://stage/grid_map.scn" id="1_t0f53"]
 [ext_resource type="Texture2D" uid="uid://qdur4kpvvtdg" path="res://stage/panorama.webp" id="2_36a8a"]
 [ext_resource type="ArrayMesh" uid="uid://ba7lhk44sk366" path="res://stage/meshes/floor.res" id="2_vkxfl"]
@@ -22,6 +23,7 @@ fog_density = 0.0015
 fog_sky_affect = 0.0
 
 [node name="Stage" type="Node3D"]
+script = ExtResource("1_re4bd")
 
 [node name="GridMap" parent="." instance=ExtResource("1_t0f53")]
 data = {
@@ -32,7 +34,7 @@ metadata/_editor_floor_ = Vector3(4, 4, 0)
 [node name="WorldEnvironment" type="WorldEnvironment" parent="."]
 environment = SubResource("Environment_vpofs")
 
-[node name="DirectionalLight" type="DirectionalLight3D" parent="."]
+[node name="DirectionalLight3D" type="DirectionalLight3D" parent="."]
 transform = Transform3D(-0.965926, -0.166366, 0.198267, 1.42109e-14, 0.766044, 0.642788, -0.258819, 0.620886, -0.739941, 0, 0, 0)
 shadow_enabled = true
 shadow_bias = 0.02
diff --git a/3d/procedural_materials/loading.tscn b/3d/procedural_materials/loading.tscn
index 2f034d34..94074504 100644
--- a/3d/procedural_materials/loading.tscn
+++ b/3d/procedural_materials/loading.tscn
@@ -25,6 +25,6 @@ offset_bottom = 24.0
 grow_horizontal = 2
 grow_vertical = 2
 theme_override_colors/font_outline_color = Color(0, 0, 0, 1)
-theme_override_constants/outline_size = 6
+theme_override_constants/outline_size = 8
 theme_override_font_sizes/font_size = 32
 text = "Generating textures, please wait…"
diff --git a/3d/procedural_materials/test.tscn b/3d/procedural_materials/test.tscn
index 7bd66b5c..b1324a8b 100644
--- a/3d/procedural_materials/test.tscn
+++ b/3d/procedural_materials/test.tscn
@@ -222,10 +222,10 @@ enable_shadows = true
 ambient_mode = 0
 
 [node name="AnimationPlayer" type="AnimationPlayer" parent="."]
-autoplay = "animate_textures"
 libraries = {
 "": SubResource("AnimationLibrary_sin37")
 }
+autoplay = "animate_textures"
 
 [node name="CameraHolder" type="Node3D" parent="."]
 transform = Transform3D(-4.37114e-08, 0, 1, 0, 1, 0, -1, 0, -4.37114e-08, 0, 0.125, 26)
diff --git a/3d/procedural_materials/tester.gd b/3d/procedural_materials/tester.gd
index 1191c173..04974797 100644
--- a/3d/procedural_materials/tester.gd
+++ b/3d/procedural_materials/tester.gd
@@ -8,6 +8,7 @@ var tester_index := 0
 var rot_x := deg_to_rad(-22.5)  # This must be kept in sync with RotationX.
 var rot_y := deg_to_rad(90)  # This must be kept in sync with CameraHolder.
 var zoom := 2.5
+var is_compatibility := false
 
 @onready var testers: Node3D = $Testers
 @onready var camera_holder: Node3D = $CameraHolder  # Has a position and rotates on Y.
@@ -15,6 +16,17 @@ var zoom := 2.5
 @onready var camera: Camera3D = $CameraHolder/RotationX/Camera3D
 
 func _ready() -> void:
+	if RenderingServer.get_current_rendering_method() == "gl_compatibility":
+		# Use PCF13 shadow filtering to improve quality (Medium maps to PCF5 instead).
+		RenderingServer.directional_soft_shadow_filter_set_quality(RenderingServer.SHADOW_QUALITY_SOFT_HIGH)
+
+		# Darken the light's energy to compensate for sRGB blending (without affecting sky rendering).
+		$DirectionalLight3D.sky_mode = DirectionalLight3D.SKY_MODE_SKY_ONLY
+		var new_light: DirectionalLight3D = $DirectionalLight3D.duplicate()
+		new_light.light_energy = 0.25
+		new_light.sky_mode = DirectionalLight3D.SKY_MODE_LIGHT_ONLY
+		add_child(new_light)
+
 	camera_holder.transform.basis = Basis.from_euler(Vector3(0, rot_y, 0))
 	rotation_x.transform.basis = Basis.from_euler(Vector3(rot_x, 0, 0))
 	update_gui()
diff --git a/3d/squash_the_creeps/Main.gd b/3d/squash_the_creeps/Main.gd
index d6d58e66..9e1b377d 100644
--- a/3d/squash_the_creeps/Main.gd
+++ b/3d/squash_the_creeps/Main.gd
@@ -4,6 +4,18 @@ extends Node
 
 
 func _ready():
+	if RenderingServer.get_current_rendering_method() == "gl_compatibility":
+		# Use PCF13 shadow filtering to improve quality (Medium maps to PCF5 instead).
+		RenderingServer.directional_soft_shadow_filter_set_quality(RenderingServer.SHADOW_QUALITY_SOFT_HIGH)
+
+		# Darken the light's energy to compensate for sRGB blending (without affecting sky rendering).
+		$DirectionalLight3D.sky_mode = DirectionalLight3D.SKY_MODE_SKY_ONLY
+		var new_light: DirectionalLight3D = $DirectionalLight3D.duplicate()
+		new_light.light_energy = 0.35
+		new_light.sky_mode = DirectionalLight3D.SKY_MODE_LIGHT_ONLY
+		add_child(new_light)
+
+
 	$UserInterface/Retry.hide()
 
 
diff --git a/3d/squash_the_creeps/Main.tscn b/3d/squash_the_creeps/Main.tscn
index cc9150fc..65564a68 100644
--- a/3d/squash_the_creeps/Main.tscn
+++ b/3d/squash_the_creeps/Main.tscn
@@ -81,7 +81,7 @@ shape = SubResource("WorldBoundaryShape3D_i5n5q")
 transform = Transform3D(1, 5.96046e-08, -1.42109e-14, 3.82137e-15, -2.18557e-07, -1, -5.96046e-08, 1, -2.18557e-07, 9.53674e-07, 10, -20)
 shape = SubResource("WorldBoundaryShape3D_i5n5q")
 
-[node name="DirectionalLight" type="DirectionalLight3D" parent="."]
+[node name="DirectionalLight3D" type="DirectionalLight3D" parent="."]
 transform = Transform3D(0.5, -0.777049, 0.382355, 0, 0.441506, 0.897258, -0.866025, -0.448629, 0.220753, 0, 12.5592, 14.7757)
 shadow_enabled = true
 shadow_bias = 0.04
diff --git a/3d/truck_town/town/town_scene.gd b/3d/truck_town/town/town_scene.gd
index 31e6c20b..25a6f4aa 100644
--- a/3d/truck_town/town/town_scene.gd
+++ b/3d/truck_town/town/town_scene.gd
@@ -10,6 +10,23 @@ enum Mood {
 
 var mood := Mood.DAY: set = set_mood
 
+# Only assigned when using the Compatibility rendering method.
+# This is used to darken the sunlight to compensate for sRGB blending (without affecting sky rendering).
+var compatibility_light: DirectionalLight3D
+
+
+func _ready() -> void:
+	if RenderingServer.get_current_rendering_method() == "gl_compatibility":
+		# Use PCF13 shadow filtering to improve quality (Medium maps to PCF5 instead).
+		RenderingServer.directional_soft_shadow_filter_set_quality(RenderingServer.SHADOW_QUALITY_SOFT_HIGH)
+
+		# Darken the light's energy to compensate for sRGB blending (without affecting sky rendering).
+		$DirectionalLight3D.sky_mode = DirectionalLight3D.SKY_MODE_SKY_ONLY
+		compatibility_light = $DirectionalLight3D.duplicate()
+		compatibility_light.light_energy = $DirectionalLight3D.light_energy * 0.2
+		compatibility_light.sky_mode = DirectionalLight3D.SKY_MODE_LIGHT_ONLY
+		add_child(compatibility_light)
+
 
 func _input(event: InputEvent) -> void:
 	if event.is_action_pressed(&"cycle_mood"):
@@ -24,8 +41,8 @@ func set_mood(p_mood: Mood) -> void:
 			$DirectionalLight3D.rotation_degrees = Vector3(-20, -150, -137)
 			$DirectionalLight3D.light_color = Color(0.414, 0.377, 0.25)
 			$DirectionalLight3D.light_energy = 4.0
-			$WorldEnvironment.environment.fog_light_color = Color(0.686, 0.6, 0.467)
 			$WorldEnvironment.environment.sky.sky_material = preload("res://town/sky_morning.tres")
+			$WorldEnvironment.environment.fog_light_color = Color(0.686, 0.6, 0.467)
 			$ArtificialLights.visible = false
 		Mood.DAY:
 			$DirectionalLight3D.rotation_degrees = Vector3(-55, -120, -31)
@@ -48,3 +65,9 @@ func set_mood(p_mood: Mood) -> void:
 			$WorldEnvironment.environment.sky.sky_material = preload("res://town/sky_night.tres")
 			$WorldEnvironment.environment.fog_light_color = Color(0.2, 0.149, 0.125)
 			$ArtificialLights.visible = true
+
+	if compatibility_light:
+		# Darken the light's energy to compensate for sRGB blending (without affecting sky rendering).
+		compatibility_light.rotation_degrees = $DirectionalLight3D.rotation_degrees
+		compatibility_light.light_color = $DirectionalLight3D.light_color
+		compatibility_light.light_energy = $DirectionalLight3D.light_energy * 0.2
diff --git a/3d/waypoints/main.gd b/3d/waypoints/main.gd
new file mode 100644
index 00000000..a3f69a8e
--- /dev/null
+++ b/3d/waypoints/main.gd
@@ -0,0 +1,13 @@
+extends Node3D
+
+func _ready() -> void:
+	if RenderingServer.get_current_rendering_method() == "gl_compatibility":
+		# Use PCF13 shadow filtering to improve quality (Medium maps to PCF5 instead).
+		RenderingServer.directional_soft_shadow_filter_set_quality(RenderingServer.SHADOW_QUALITY_SOFT_HIGH)
+
+		# Darken the light's energy to compensate for sRGB blending (without affecting sky rendering).
+		$Sun.sky_mode = DirectionalLight3D.SKY_MODE_SKY_ONLY
+		var new_light: DirectionalLight3D = $Sun.duplicate()
+		new_light.light_energy = 0.35
+		new_light.sky_mode = DirectionalLight3D.SKY_MODE_LIGHT_ONLY
+		add_child(new_light)
diff --git a/3d/waypoints/main.tscn b/3d/waypoints/main.tscn
index 6019baa9..7c74ecef 100644
--- a/3d/waypoints/main.tscn
+++ b/3d/waypoints/main.tscn
@@ -1,6 +1,7 @@
-[gd_scene load_steps=18 format=3 uid="uid://rj7yrj3c672g"]
+[gd_scene load_steps=19 format=3 uid="uid://rj7yrj3c672g"]
 
-[ext_resource type="Script" uid="uid://cx0dkr482ui5p" path="res://camera.gd" id="1"]
+[ext_resource type="Script" path="res://camera.gd" id="1"]
+[ext_resource type="Script" path="res://main.gd" id="1_nvv4i"]
 [ext_resource type="PackedScene" uid="uid://deqpan4silm2n" path="res://waypoint.tscn" id="2"]
 
 [sub_resource type="StandardMaterial3D" id="5"]
@@ -54,6 +55,7 @@ sky = SubResource("Sky_47fsp")
 tonemap_mode = 4
 
 [node name="Main" type="Node3D"]
+script = ExtResource("1_nvv4i")
 
 [node name="BlueCube" type="MeshInstance3D" parent="."]
 transform = Transform3D(1, 0, 0, 0, 1, 0, 0, 0, 1, 5, 0, -5)
@@ -124,8 +126,8 @@ mesh = SubResource("4")
 [node name="Environment" type="WorldEnvironment" parent="."]
 environment = SubResource("Environment_ob0ys")
 
-[node name="Sun" type="DirectionalLight3D" parent="Environment"]
-transform = Transform3D(-0.866025, -0.433013, 0.25, 0, 0.5, 0.866026, -0.5, 0.75, -0.433013, 0, 0, 0)
+[node name="Sun" type="DirectionalLight3D" parent="."]
+transform = Transform3D(-0.866025, -0.433013, 0.25, 0, 0.5, 0.866025, -0.5, 0.75, -0.433013, 0, 0, 0)
 shadow_enabled = true
 shadow_bias = 0.04
 shadow_blur = 1.5
diff --git a/gui/bidi_and_font_features/bidi.gd b/gui/bidi_and_font_features/bidi.gd
index 27ac3104..1dc9e3bd 100644
--- a/gui/bidi_and_font_features/bidi.gd
+++ b/gui/bidi_and_font_features/bidi.gd
@@ -2,7 +2,15 @@ extends Control
 
 @onready var variable_font_variation: FontVariation = $"TabContainer/Variable fonts/VariableFontPreview".get_theme_font("font")
 
+
 func _ready() -> void:
+	if OS.has_feature("web"):
+		$"TabContainer/System fonts/LabelVarInfo".text = "Loading system fonts is not supported on the Web platform."
+		$"TabContainer/System fonts/ValueSetter".visible = false
+		$"TabContainer/System fonts/Italic".visible = false
+		$"TabContainer/System fonts/Weight".visible = false
+		$"TabContainer/System fonts/VBoxContainer".visible = false
+
 	var tree: Tree = $"TabContainer/Text direction/Tree"
 	var root := tree.create_item()
 	tree.set_hide_root(true)
@@ -15,6 +23,7 @@ func _ready() -> void:
 	var fourth := tree.create_item(third)
 	fourth.set_text(0, "fourth")
 
+
 func _on_Tree_item_selected() -> void:
 	var tree: Tree = $"TabContainer/Text direction/Tree"
 	var path := ""
@@ -25,12 +34,15 @@ func _on_Tree_item_selected() -> void:
 	$"TabContainer/Text direction/LineEditST".text = path
 	$"TabContainer/Text direction/LineEditNoST".text = path
 
+
 func _on_LineEditCustomSTDst_text_changed(new_text: String) -> void:
 	$"TabContainer/Text direction/LineEditCustomSTSource".text = new_text
 
+
 func _on_LineEditCustomSTSource_text_changed(new_text: String) -> void:
 	$"TabContainer/Text direction/LineEditCustomSTDst".text = new_text
 
+
 func _on_LineEditCustomSTDst_tree_entered() -> void:
 	# Refresh text to apply custom script once it's loaded.
 	$"TabContainer/Text direction/LineEditCustomSTDst".text = $"TabContainer/Text direction/LineEditCustomSTSource".text
@@ -123,7 +135,3 @@ func _on_system_font_italic_toggled(button_pressed: bool) -> void:
 func _on_system_font_name_text_changed(new_text: String) -> void:
 	var system_font: SystemFont = $"TabContainer/System fonts/VBoxContainer/Custom/FontName".get_theme_font("font")
 	system_font.font_names[0] = new_text
-
-
-
-
diff --git a/gui/bidi_and_font_features/bidi.tscn b/gui/bidi_and_font_features/bidi.tscn
index 38dc9520..2c739b4e 100644
--- a/gui/bidi_and_font_features/bidi.tscn
+++ b/gui/bidi_and_font_features/bidi.tscn
@@ -84,9 +84,12 @@ anchor_bottom = 1.0
 grow_horizontal = 2
 grow_vertical = 2
 theme_override_font_sizes/font_size = 14
+current_tab = 3
 
 [node name="Line breaking and justification" type="Panel" parent="TabContainer"]
+visible = false
 layout_mode = 2
+metadata/_tab_index = 0
 
 [node name="LabelBrkInfo" type="Label" parent="TabContainer/Line breaking and justification"]
 layout_mode = 0
@@ -165,6 +168,7 @@ text = "آنچ اندر وهم ناید آن شوم"
 [node name="Text direction" type="Panel" parent="TabContainer"]
 visible = false
 layout_mode = 2
+metadata/_tab_index = 1
 
 [node name="LabelDirInfo" type="Label" parent="TabContainer/Text direction"]
 layout_mode = 0
@@ -349,6 +353,7 @@ script = ExtResource("3")
 [node name="Font features" type="Panel" parent="TabContainer"]
 visible = false
 layout_mode = 2
+metadata/_tab_index = 2
 
 [node name="LabelDisplay1" type="Label" parent="TabContainer/Font features"]
 layout_mode = 0
@@ -489,8 +494,8 @@ Que fin 1/3 0
 [opentype_features=frac=1,zero]Que fin 1/3 0[/opentype_features] [color=#fffa](frac=1,zero - fractions and slashed zero)[/color][/font_size]"
 
 [node name="Variable fonts" type="Panel" parent="TabContainer"]
-visible = false
 layout_mode = 2
+metadata/_tab_index = 3
 
 [node name="LabelVarInfo" type="Label" parent="TabContainer/Variable fonts"]
 layout_mode = 0
@@ -621,6 +626,7 @@ uri = "https://www.recursive.design/"
 [node name="System fonts" type="Panel" parent="TabContainer"]
 visible = false
 layout_mode = 2
+metadata/_tab_index = 4
 
 [node name="LabelVarInfo" type="Label" parent="TabContainer/System fonts"]
 layout_mode = 0
diff --git a/misc/os_test/actions.gd b/misc/os_test/actions.gd
index a147fb40..217db828 100644
--- a/misc/os_test/actions.gd
+++ b/misc/os_test/actions.gd
@@ -1,5 +1,21 @@
 extends Node
 
+func _ready() -> void:
+	if OS.has_feature("web"):
+		for button: Button in [
+			$GridContainer/OpenShellFolder,
+			$GridContainer/MoveWindowToForeground,
+			$GridContainer/RequestAttention,
+			$GridContainer/VibrateDeviceShort,
+			$GridContainer/VibrateDeviceLong,
+			$GridContainer/AddGlobalMenuItems,
+			$GridContainer/RemoveGlobalMenuItem,
+			$GridContainer/KillCurrentProcess,
+		]:
+			button.disabled = true
+			button.text += "\n(not supported on Web)"
+
+
 func _on_open_shell_web_pressed() -> void:
 	OS.shell_open("https://example.com")
 
diff --git a/misc/os_test/os_test.gd b/misc/os_test/os_test.gd
index e09415ee..24f31da7 100644
--- a/misc/os_test/os_test.gd
+++ b/misc/os_test/os_test.gd
@@ -211,7 +211,7 @@ func _ready() -> void:
 	add_header("Video")
 	add_line("Adapter name", RenderingServer.get_video_adapter_name())
 	add_line("Adapter vendor", RenderingServer.get_video_adapter_vendor())
-	if ProjectSettings.get_setting_with_override("rendering/renderer/rendering_method") != "gl_compatibility":
+	if RenderingServer.get_current_rendering_method() != "gl_compatibility":
 		# Querying the adapter type isn't supported in Compatibility.
 		add_line("Adapter type", [
 			"Other (Unknown)",
diff --git a/misc/window_management/control.gd b/misc/window_management/control.gd
index 96ce748b..724495a9 100644
--- a/misc/window_management/control.gd
+++ b/misc/window_management/control.gd
@@ -4,7 +4,22 @@ var mouse_position := Vector2()
 
 @onready var observer: CharacterBody3D = $"../Observer"
 
+
 func _ready() -> void:
+	if OS.has_feature("web"):
+		for button: BaseButton in [
+			$Buttons/Button_FixedSize,
+			$Buttons/Button_Minimized,
+			$Buttons/Button_Maximized,
+			$Buttons/Button_MoveTo,
+			$Buttons/Button_Resize,
+			$Buttons/Button_MouseModeConfined,
+			$Buttons/Button_MouseModeConfinedHidden,
+			$CheckButton,
+		]:
+			button.disabled = true
+			button.text += " (not supported on Web)"
+
 	if not check_wm_api():
 		set_physics_process(false)
 		set_process_input(false)
@@ -35,7 +50,8 @@ func _physics_process(_delta: float) -> void:
 	$Labels/Label_Mode.text = modetext
 	$Labels/Label_Position.text = str("Position: ", DisplayServer.window_get_position())
 	$Labels/Label_Size.text = str("Size: ", DisplayServer.window_get_size())
-	$Labels/Label_MousePosition.text = str("Mouse Position: ", mouse_position)
+	# Pad decimals when showing mouse position, as some platforms report floating-point mouse positions.
+	$Labels/Label_MousePosition.text = str("Mouse Position: %.4v" % mouse_position)
 	$Labels/Label_Screen_Count.text = str("Screen_Count: ", DisplayServer.get_screen_count())
 	$Labels/Label_Screen_Current.text = str("Screen: ", DisplayServer.window_get_current_screen())
 	$Labels/Label_Screen0_Resolution.text = str("Screen0 Resolution:\n", DisplayServer.screen_get_size())
diff --git a/misc/window_management/observer/observer.gd b/misc/window_management/observer/observer.gd
index e7b0155c..9f2520f9 100644
--- a/misc/window_management/observer/observer.gd
+++ b/misc/window_management/observer/observer.gd
@@ -12,6 +12,7 @@ var state := State.MENU
 
 @onready var camera: Camera3D = $Camera3D
 
+
 func _process(delta: float) -> void:
 	if state != State.GRAB:
 		return
diff --git a/misc/window_management/window_management.tscn b/misc/window_management/window_management.tscn
index 26f3feed..a6f8655f 100644
--- a/misc/window_management/window_management.tscn
+++ b/misc/window_management/window_management.tscn
@@ -135,7 +135,7 @@ metadata/_edit_use_custom_anchors = false
 layout_mode = 2
 size_flags_horizontal = 2
 size_flags_vertical = 0
-text = "MouseModes:"
+text = "Mouse Modes:"
 metadata/_edit_layout_mode = 1
 metadata/_edit_use_custom_anchors = false