diff --git a/.gitignore b/.gitignore
index e8b2308..aea3f71 100644
--- a/.gitignore
+++ b/.gitignore
@@ -3,8 +3,9 @@ fonts/
 maps/
 bin/
 dist/
+rtp/
 dev-assets/guidebook/venv
-dev-assets/guidebook/compiled/pages
+dev-assets/guidebook/site/
 wasm/assets/
 *.wasm
 *.doodad
@@ -15,3 +16,4 @@ docker/fedora
 screenshot-*.png
 map-*.json
 pkg/wallpaper/*.png
+
diff --git a/Building.md b/Building.md
index 6ffe704..0f075f2 100644
--- a/Building.md
+++ b/Building.md
@@ -84,10 +84,10 @@ Dependencies are Go, SDL2 and SDL2_ttf:
 
 ```bash
 # Fedora
-sudo dnf -y install golang SDL2-devel SDL2_ttf-devel
+sudo dnf -y install golang SDL2-devel SDL2_ttf-devel SDL2_mixer-devel
 
 # Ubuntu and Debian
-sudo apt -y install golang libsdl2-dev libsdl2-ttf-dev
+sudo apt -y install golang libsdl2-dev libsdl2-ttf-dev libsdl2-mixer-devel
 ```
 
 ## Mac OS
diff --git a/cmd/doodle/main.go b/cmd/doodle/main.go
index f6e459f..74f2e03 100644
--- a/cmd/doodle/main.go
+++ b/cmd/doodle/main.go
@@ -12,6 +12,7 @@ import (
 	"git.kirsle.net/apps/doodle/pkg/balance"
 	"git.kirsle.net/apps/doodle/pkg/bindata"
 	"git.kirsle.net/apps/doodle/pkg/branding"
+	"git.kirsle.net/apps/doodle/pkg/sound"
 	"git.kirsle.net/go/render/sdl"
 	"github.com/urfave/cli"
 
@@ -95,6 +96,9 @@ func main() {
 			panic(err)
 		}
 
+		// Preload all sound effects.
+		sound.PreloadAll()
+
 		game := doodle.New(c.Bool("debug"), engine)
 		game.SetupEngine()
 		if c.Bool("guitest") {
diff --git a/dev-assets/doodads/buttons/button.js b/dev-assets/doodads/buttons/button.js
index ceac9e7..c9c8237 100644
--- a/dev-assets/doodads/buttons/button.js
+++ b/dev-assets/doodads/buttons/button.js
@@ -2,6 +2,7 @@ function main() {
 	console.log("%s initialized!", Self.Title);
 
 	var timer = 0;
+	var pressed = false;
 
 	Events.OnCollide(function(e) {
 		if (!e.Settled) {
@@ -13,7 +14,12 @@ function main() {
 			return;
 		}
 
-		Message.Publish("power", true);
+		if (!pressed) {
+			Sound.Play("button-down.wav")
+			Message.Publish("power", true);
+			pressed = true;
+		}
+
 
 		if (timer > 0) {
 			clearTimeout(timer);
@@ -21,9 +27,11 @@ function main() {
 
 		Self.ShowLayer(1);
 		timer = setTimeout(function() {
+			Sound.Play("button-up.wav")
 			Self.ShowLayer(0);
 			Message.Publish("power", false);
 			timer = 0;
+			pressed = false;
 		}, 200);
 	});
 }
diff --git a/dev-assets/doodads/buttons/sticky.js b/dev-assets/doodads/buttons/sticky.js
index 9d1893e..9dac758 100644
--- a/dev-assets/doodads/buttons/sticky.js
+++ b/dev-assets/doodads/buttons/sticky.js
@@ -8,6 +8,7 @@ function main() {
 		if (powered && pressed) {
 			Self.ShowLayer(0);
 			pressed = false;
+			Sound.Play("button-up.wav")
 			Message.Publish("power", false);
 		}
 	})
@@ -26,6 +27,7 @@ function main() {
 			return;
 		}
 
+		Sound.Play("button-down.wav")
 		Self.ShowLayer(1);
 		pressed = true;
 		Message.Publish("power", true);
diff --git a/dev-assets/doodads/crumbly-floor/crumbly-floor.js b/dev-assets/doodads/crumbly-floor/crumbly-floor.js
index 509101b..97c2be0 100644
--- a/dev-assets/doodads/crumbly-floor/crumbly-floor.js
+++ b/dev-assets/doodads/crumbly-floor/crumbly-floor.js
@@ -43,6 +43,7 @@ function main() {
 				Self.PlayAnimation("shake", function() {
 					state = stateFalling;
 					Self.PlayAnimation("fall", function() {
+						Sound.Play("crumbly-break.wav")
 						state = stateFallen;
 						Self.ShowLayerNamed("fallen");
 
diff --git a/dev-assets/doodads/doors/colored-door.js b/dev-assets/doodads/doors/colored-door.js
index f3e12fc..1967449 100644
--- a/dev-assets/doodads/doors/colored-door.js
+++ b/dev-assets/doodads/doors/colored-door.js
@@ -32,6 +32,7 @@ function main() {
 			if (unlocked) {
 				Self.ShowLayer(enterSide < 0 ? layer.right : layer.left);
 				opened = true;
+				Sound.Play("door-open.wav")
 				return;
 			}
 
@@ -45,11 +46,13 @@ function main() {
 			if (e.Settled) {
 				unlocked = true;
 				Self.ShowLayer(enterSide < 0 ? layer.right : layer.left);
+				Sound.Play("unlock.wav")
 			}
 		}
 	});
 	Events.OnLeave(function(e) {
 		Self.ShowLayer(layer.closed);
+		// Sound.Play("door-close.wav")
 
 		// Reset collision state.
 		opened = false;
diff --git a/dev-assets/doodads/doors/electric-door.js b/dev-assets/doodads/doors/electric-door.js
index 1642890..43056c6 100644
--- a/dev-assets/doodads/doors/electric-door.js
+++ b/dev-assets/doodads/doors/electric-door.js
@@ -17,12 +17,14 @@ function main() {
 			}
 
 			animating = true;
+			Sound.Play("electric-door.wav")
 			Self.PlayAnimation("open", function() {
 				opened = true;
 				animating = false;
 			});
 		} else {
 			animating = true;
+			Sound.Play("electric-door.wav")
 			Self.PlayAnimation("close", function() {
 				opened = false;
 				animating = false;
diff --git a/dev-assets/doodads/doors/keys.js b/dev-assets/doodads/doors/keys.js
index 159069e..00cc6d7 100644
--- a/dev-assets/doodads/doors/keys.js
+++ b/dev-assets/doodads/doors/keys.js
@@ -3,6 +3,7 @@ function main() {
 
 	Events.OnCollide(function(e) {
 		if (e.Settled) {
+			Sound.Play("item-get.wav")
 			e.Actor.AddItem(Self.Filename, 0);
 			Self.Destroy();
 		}
diff --git a/dev-assets/doodads/switches/switch.js b/dev-assets/doodads/switches/switch.js
index c36b2de..c62689a 100644
--- a/dev-assets/doodads/switches/switch.js
+++ b/dev-assets/doodads/switches/switch.js
@@ -19,6 +19,7 @@ function main() {
 		}
 
 		if (collide === false) {
+			Sound.Play("button-down.wav")
 			state = !state;
 			Message.Publish("power", state);
 			showState(state);
diff --git a/dev-assets/guidebook/pages/DoodadScripts.md b/dev-assets/guidebook/docs/custom-doodads/scripts.md
similarity index 100%
rename from dev-assets/guidebook/pages/DoodadScripts.md
rename to dev-assets/guidebook/docs/custom-doodads/scripts.md
diff --git a/pkg/scripting/js_api.go b/pkg/scripting/js_api.go
index 54a57fa..5323619 100644
--- a/pkg/scripting/js_api.go
+++ b/pkg/scripting/js_api.go
@@ -6,6 +6,7 @@ import (
 	"git.kirsle.net/apps/doodle/pkg/log"
 	"git.kirsle.net/apps/doodle/pkg/physics"
 	"git.kirsle.net/apps/doodle/pkg/shmem"
+	"git.kirsle.net/apps/doodle/pkg/sound"
 	"git.kirsle.net/go/render"
 )
 
@@ -25,6 +26,11 @@ func NewJSProxy(vm *VM) JSProxy {
 			"error": log.Error,
 		},
 
+		// Audio API.
+		"Sound": map[string]interface{}{
+			"Play": sound.PlaySound,
+		},
+
 		// Type constructors.
 		"RGBA":   render.RGBA,
 		"Point":  render.NewPoint,
diff --git a/pkg/sound/preload.go b/pkg/sound/preload.go
new file mode 100644
index 0000000..b51546d
--- /dev/null
+++ b/pkg/sound/preload.go
@@ -0,0 +1,25 @@
+package sound
+
+import (
+	"io/ioutil"
+	"path/filepath"
+)
+
+// PreloadAll looks in the SoundRoot and MusicRoot folders and preloads all
+// supported files into the caches.
+func PreloadAll() {
+	if engine == nil || !Enabled {
+		return
+	}
+
+	// Preload sound effects.
+	if files, err := ioutil.ReadDir(SoundRoot); err == nil {
+		for _, file := range files {
+			if filepath.Ext(file.Name()) != ".wav" {
+				continue
+			}
+
+			LoadSound(file.Name())
+		}
+	}
+}
diff --git a/pkg/sound/sound.go b/pkg/sound/sound.go
new file mode 100644
index 0000000..45de411
--- /dev/null
+++ b/pkg/sound/sound.go
@@ -0,0 +1,114 @@
+// Package sound provides audio functions for Doodle.
+package sound
+
+import (
+	"path/filepath"
+	"sync"
+
+	"git.kirsle.net/apps/doodle/pkg/log"
+	"git.kirsle.net/go/audio/sdl"
+	"github.com/veandco/go-sdl2/mix"
+)
+
+// Globals.
+var (
+	// If enabled is false, all sound functions are no-ops.
+	Enabled bool
+
+	// Root folder on disk where sound and music files should live.
+	SoundRoot = filepath.Join("rtp", "sfx")
+	MusicRoot = filepath.Join("rtp", "music")
+
+	// Cache of loaded music and sound effects.
+	music  = map[string]*sdl.Track{}
+	sounds = map[string]*sdl.Track{}
+	mu     sync.RWMutex
+
+	engine *sdl.Engine
+)
+
+// Initialize SDL2 Audio at startup.
+func init() {
+	eng, err := sdl.New(mix.INIT_MP3 | mix.INIT_OGG)
+	if err != nil {
+		log.Error("sound.init(): error initializing SDL2 audio: %s", err)
+		return
+	}
+
+	err = eng.Setup()
+	if err != nil {
+		log.Error("sound.init(): error setting up SDL2 audio: %s", err)
+		return
+	}
+
+	engine = eng
+	Enabled = true
+}
+
+// LoadMusic loads filename from the MusicRoot into the global music cache.
+// If the music is already loaded, does nothing.
+func LoadMusic(filename string) *sdl.Track {
+	if engine == nil || !Enabled {
+		return nil
+	}
+
+	// Check if the music is already loaded.
+	mu.RLock()
+	mus, ok := music[filename]
+	mu.RUnlock()
+	if ok {
+		return mus
+	}
+
+	// Load the music in.
+	track, err := engine.LoadMusic(filepath.Join(MusicRoot, filename))
+	if err != nil {
+		log.Error("sound.LoadMusic: failed to load file %s: %s", filename, err)
+		return nil
+	}
+
+	mu.Lock()
+	music[filename] = &track
+	mu.Unlock()
+
+	return &track
+}
+
+// LoadSound loads filename from the SoundRoot into the global SFX cache.
+// If the sound is already loaded, does nothing.
+func LoadSound(filename string) *sdl.Track {
+	if engine == nil || !Enabled {
+		return nil
+	}
+
+	// Check if the music is already loaded.
+	mu.RLock()
+	sfx, ok := sounds[filename]
+	mu.RUnlock()
+	if ok {
+		return sfx
+	}
+
+	// Load the sound in.
+	log.Info("Loading sound: %s", filename)
+	track, err := engine.LoadSound(filepath.Join(SoundRoot, filename))
+	if err != nil {
+		log.Error("sound.LoadSound: failed to load file %s: %s", filename, err)
+		return nil
+	}
+
+	mu.Lock()
+	sounds[filename] = &track
+	mu.Unlock()
+
+	return &track
+}
+
+// PlaySound plays the named sound.
+func PlaySound(filename string) {
+	log.Debug("Play sound: %s", filename)
+	sound := LoadSound(filename)
+	if sound != nil {
+		sound.Play(1)
+	}
+}