diff --git a/readme_images.htm b/readme_images.htm
index c5fafbc..a713944 100644
--- a/readme_images.htm
+++ b/readme_images.htm
@@ -14,12 +14,12 @@
 <title>Readme Image Generator</title>
 <link rel="icon" href="favicon.png">
 
-<link rel="stylesheet" href="styles/readme_images.css">
+<link rel="stylesheet" href="styles/readmeImages.css">
 
 <script src="scripts/requireConfig.js"></script>
 
 <script
-	data-main="scripts/readme_images"
+	data-main="scripts/readmeImages"
 	src="https://cdnjs.cloudflare.com/ajax/libs/require.js/2.3.5/require.min.js"
 	integrity="sha256-0SGl1PJNDyJwcV5T+weg2zpEMrh7xvlwO4oXgvZCeZk="
 	crossorigin="anonymous"
diff --git a/scripts/interface/Interface.js b/scripts/interface/Interface.js
index 7916d84..318455f 100644
--- a/scripts/interface/Interface.js
+++ b/scripts/interface/Interface.js
@@ -43,23 +43,19 @@ define([
 
 	return class Interface {
 		constructor({
-			parser,
-			generator,
-			renderer,
-			exporter,
+			sequenceDiagram,
 			defaultCode = '',
 			localStorage = '',
 			library = null,
 		}) {
-			this.parser = parser;
-			this.generator = generator;
-			this.renderer = renderer;
-			this.exporter = exporter;
+			this.diagram = sequenceDiagram;
 			this.defaultCode = defaultCode;
 			this.localStorage = localStorage;
 			this.library = library;
 			this.minScale = 1.5;
 
+			this.diagram.registerCodeMirrorMode(CodeMirror);
+
 			this.debounced = null;
 			this.latestSeq = null;
 			this.renderedSeq = null;
@@ -114,20 +110,11 @@ define([
 
 		buildEditor(container) {
 			const value = this.loadCode() || this.defaultCode;
-			CodeMirror.defineMode(
-				'sequence',
-				() => this.parser.getCodeMirrorMode()
-			);
-			CodeMirror.registerHelper(
-				'hint',
-				'sequence',
-				this.parser.getCodeMirrorHints()
-			);
 			const code = new CodeMirror(container, {
 				value,
 				mode: 'sequence',
 				globals: {
-					themes: this.renderer.getThemeNames(),
+					themes: this.diagram.getThemeNames(),
 				},
 				lineNumbers: true,
 				showTrailingSpace: true,
@@ -167,10 +154,10 @@ define([
 			this.code.on('cursorActivity', () => {
 				const from = this.code.getCursor('from').line;
 				const to = this.code.getCursor('to').line;
-				this.renderer.setHighlight(Math.min(from, to));
+				this.diagram.setHighlight(Math.min(from, to));
 			});
 
-			this.renderer.addEventListener('mouseover', (element) => {
+			this.diagram.addEventListener('mouseover', (element) => {
 				if(this.marker) {
 					this.marker.clear();
 				}
@@ -188,14 +175,14 @@ define([
 				}
 			});
 
-			this.renderer.addEventListener('mouseout', () => {
+			this.diagram.addEventListener('mouseout', () => {
 				if(this.marker) {
 					this.marker.clear();
 					this.marker = null;
 				}
 			});
 
-			this.renderer.addEventListener('click', (element) => {
+			this.diagram.addEventListener('click', (element) => {
 				if(this.marker) {
 					this.marker.clear();
 					this.marker = null;
@@ -226,12 +213,10 @@ define([
 				);
 				container.appendChild(hold);
 				try {
-					const preview = simplifyPreview(lib.preview || lib.code);
-					const parsed = this.parser.parse(preview);
-					const generated = this.generator.generate(parsed);
-					const rendering = this.renderer.clone();
-					holdInner.appendChild(rendering.svg());
-					rendering.render(generated);
+					this.diagram.clone({
+						code: simplifyPreview(lib.preview || lib.code),
+						container: holdInner,
+					});
 				} catch(e) {
 					hold.setAttribute('class', 'library-item broken');
 					holdInner.appendChild(makeText(lib.code));
@@ -286,7 +271,7 @@ define([
 			container.appendChild(this.buildViewPane());
 
 			this.code = this.buildEditor(codePane);
-			this.viewPaneInner.appendChild(this.renderer.svg());
+			this.viewPaneInner.appendChild(this.diagram.dom());
 
 			this.registerListeners();
 			this.update();
@@ -306,7 +291,7 @@ define([
 			this.code.focus();
 		}
 
-		updateMinSize(width, height) {
+		updateMinSize({width, height}) {
 			const style = this.viewPaneInner.style;
 			style.minWidth = Math.ceil(width * this.minScale) + 'px';
 			style.minHeight = Math.ceil(height * this.minScale) + 'px';
@@ -317,8 +302,8 @@ define([
 			this.debounced = null;
 			this.pngDirty = true;
 			this.renderedSeq = sequence;
-			this.renderer.render(sequence);
-			this.updateMinSize(this.renderer.width, this.renderer.height);
+			this.diagram.render(sequence);
+			this.updateMinSize(this.diagram.getSize());
 		}
 
 		saveCode(src) {
@@ -362,8 +347,7 @@ define([
 			this.saveCode(src);
 			let sequence = null;
 			try {
-				const parsed = this.parser.parse(src);
-				sequence = this.generator.generate(parsed);
+				sequence = this.diagram.process(src);
 			} catch(e) {
 				this.markError(e);
 				return;
@@ -403,16 +387,13 @@ define([
 			}
 			this.pngDirty = false;
 			this.updatingPNG = true;
-			this.exporter.getPNGURL(
-				this.renderer,
-				PNG_RESOLUTION,
-				(url, latest) => {
+			this.diagram.getPNG({resolution: PNG_RESOLUTION})
+				.then(({url, latest}) => {
 					if(latest) {
 						this.downloadPNG.setAttribute('href', url);
 						this.updatingPNG = false;
 					}
-				}
-			);
+				});
 			return true;
 		}
 
@@ -430,7 +411,7 @@ define([
 
 		_downloadSVGClick() {
 			this.forceRender();
-			const url = this.exporter.getSVGURL(this.renderer);
+			const url = this.diagram.getSVGSynchronous();
 			this.downloadSVG.setAttribute('href', url);
 		}
 	};
diff --git a/scripts/interface/Interface_spec.js b/scripts/interface/Interface_spec.js
index 7af60bd..07e2b59 100644
--- a/scripts/interface/Interface_spec.js
+++ b/scripts/interface/Interface_spec.js
@@ -4,44 +4,33 @@ defineDescribe('Interface', ['./Interface'], (Interface) => {
 	// Thanks, https://stackoverflow.com/a/23522755/1180785
 	const safari = /^((?!chrome|android).)*safari/i.test(navigator.userAgent);
 
-	let parser = null;
-	let generator = null;
-	let renderer = null;
-	let exporter = null;
+	let sequenceDiagram = null;
 	let container = null;
 	let ui = null;
 
 	beforeEach(() => {
-		parser = jasmine.createSpyObj('parser', [
-			'parse',
-			'getCodeMirrorMode',
-			'getCodeMirrorHints',
+		sequenceDiagram = jasmine.createSpyObj('sequenceDiagram', [
+			'dom',
+			'render',
+			'clone',
+			'getSize',
+			'process',
+			'getThemeNames',
+			'addEventListener',
+			'registerCodeMirrorMode',
+			'getSVGSynchronous',
 		]);
-		parser.parse.and.returnValue({
-			meta: {},
-			stages: [],
-		});
-		generator = jasmine.createSpyObj('generator', ['generate']);
-		generator.generate.and.returnValue({
+		sequenceDiagram.process.and.returnValue({
 			meta: {},
 			agents: [],
 			stages: [],
 		});
-		renderer = jasmine.createSpyObj('renderer', [
-			'render',
-			'svg',
-			'getThemeNames',
-			'addEventListener',
-		]);
-		renderer.svg.and.returnValue(document.createElement('svg'));
+		sequenceDiagram.getSize.and.returnValue({width: 10, height: 20});
+		sequenceDiagram.dom.and.returnValue(document.createElement('svg'));
 		container = jasmine.createSpyObj('container', ['appendChild']);
-		exporter = jasmine.createSpyObj('exporter', ['getSVGURL']);
 
 		ui = new Interface({
-			parser,
-			generator,
-			renderer,
-			exporter,
+			sequenceDiagram,
 			defaultCode: 'my default code',
 		});
 	});
@@ -61,7 +50,7 @@ defineDescribe('Interface', ['./Interface'], (Interface) => {
 
 	describe('download SVG', () => {
 		it('triggers a download of the current image in SVG format', () => {
-			exporter.getSVGURL.and.returnValue('mySVGURL');
+			sequenceDiagram.getSVGSynchronous.and.returnValue('mySVGURL');
 			ui.build(container);
 
 			expect(ui.downloadSVG.getAttribute('href')).toEqual('#');
diff --git a/scripts/main.js b/scripts/main.js
index 45d0fe9..1d0a620 100644
--- a/scripts/main.js
+++ b/scripts/main.js
@@ -3,25 +3,13 @@
 
 	requirejs.config(window.getRequirejsCDN());
 
-	/* jshint -W072 */ // Allow several required modules
 	requirejs([
 		'interface/Interface',
-		'interface/Exporter',
-		'sequence/Parser',
-		'sequence/Generator',
-		'sequence/Renderer',
-		'sequence/themes/Basic',
-		'sequence/themes/Chunky',
+		'sequence/SequenceDiagram',
 	], (
 		Interface,
-		Exporter,
-		Parser,
-		Generator,
-		Renderer,
-		BasicTheme,
-		ChunkyTheme
+		SequenceDiagram
 	) => {
-		/* jshint +W072 */
 		const defaultCode = (
 			'title Labyrinth\n' +
 			'\n' +
@@ -236,13 +224,7 @@
 		];
 		const ui = new Interface({
 			defaultCode,
-			parser: new Parser(),
-			generator: new Generator(),
-			renderer: new Renderer({themes: [
-				new BasicTheme(),
-				new ChunkyTheme(),
-			]}),
-			exporter: new Exporter(),
+			sequenceDiagram: new SequenceDiagram(),
 			library,
 			localStorage: 'src',
 		});
diff --git a/scripts/readme_images.js b/scripts/readmeImages.js
similarity index 73%
rename from scripts/readme_images.js
rename to scripts/readmeImages.js
index 1428397..2fdf1e8 100644
--- a/scripts/readme_images.js
+++ b/scripts/readmeImages.js
@@ -63,42 +63,15 @@
 		}
 	}
 
-	/* jshint -W072 */ // Allow several required modules
-	requirejs([
-		'sequence/Parser',
-		'sequence/Generator',
-		'sequence/Renderer',
-		'sequence/themes/Basic',
-		'sequence/themes/Chunky',
-		'interface/Exporter',
-	], (
-		Parser,
-		Generator,
-		Renderer,
-		BasicTheme,
-		ChunkyTheme,
-		Exporter
-	) => {
-		/* jshint +W072 */
-		const parser = new Parser();
-		const generator = new Generator();
-		const themes = [
-			new BasicTheme(),
-			new ChunkyTheme(),
-		];
-
+	requirejs(['sequence/SequenceDiagram'], (SequenceDiagram) => {
 		const status = makeNode('div', {'class': 'status'});
 		const statusText = makeText('Loading\u2026');
 		status.appendChild(statusText);
 		document.body.appendChild(status);
 
 		function renderSample({file, code, size}) {
-			const renderer = new Renderer({themes});
-			const exporter = new Exporter();
-
 			const hold = makeNode('div', {'class': 'hold'});
-
-			hold.appendChild(renderer.svg());
+			const diagram = new SequenceDiagram(code, {container: hold});
 
 			const raster = makeNode('img', {
 				'src': '',
@@ -122,14 +95,7 @@
 
 			document.body.appendChild(hold);
 
-			const parsed = parser.parse(code);
-			const sequence = generator.generate(parsed);
-			renderer.render(sequence);
-			if(size) {
-				renderer.width = size.width;
-				renderer.height = size.height;
-			}
-			exporter.getPNGURL(renderer, PNG_RESOLUTION, (url) => {
+			diagram.getPNG({resolution: PNG_RESOLUTION, size}).then(({url}) => {
 				raster.setAttribute('src', url);
 				downloadPNG.setAttribute('href', url);
 			});
diff --git a/scripts/interface/Exporter.js b/scripts/sequence/Exporter.js
similarity index 100%
rename from scripts/interface/Exporter.js
rename to scripts/sequence/Exporter.js
diff --git a/scripts/sequence/Renderer.js b/scripts/sequence/Renderer.js
index fc32e93..651d8c6 100644
--- a/scripts/sequence/Renderer.js
+++ b/scripts/sequence/Renderer.js
@@ -98,13 +98,8 @@ define([
 			});
 		}
 
-		clone({namespace = null} = {}) {
-			return new Renderer({
-				themes: this.getThemes(),
-				namespace,
-				components: this.components,
-				SVGTextBlockClass: this.SVGTextBlockClass,
-			});
+		addTheme(theme) {
+			this.themes.set(theme.name, theme);
 		}
 
 		buildStaticElements() {
diff --git a/scripts/sequence/SequenceDiagram.js b/scripts/sequence/SequenceDiagram.js
new file mode 100644
index 0000000..cf2b8b4
--- /dev/null
+++ b/scripts/sequence/SequenceDiagram.js
@@ -0,0 +1,217 @@
+/* jshint -W072 */ // Allow several required modules
+define([
+	'core/EventObject',
+	'./Parser',
+	'./Generator',
+	'./Renderer',
+	'./Exporter',
+	'./themes/Basic',
+	'./themes/Chunky',
+], (
+	EventObject,
+	Parser,
+	Generator,
+	Renderer,
+	Exporter,
+	BasicTheme,
+	ChunkyTheme
+) => {
+	/* jshint +W072 */
+	'use strict';
+
+	const themes = [
+		new BasicTheme(),
+		new ChunkyTheme(),
+	];
+
+	const SharedParser = new Parser();
+	const SharedGenerator = new Generator();
+	const CMMode = SharedParser.getCodeMirrorMode();
+	const CMHints = SharedParser.getCodeMirrorHints();
+
+	function registerCodeMirrorMode(CodeMirror, modeName = 'sequence') {
+		if(!CodeMirror) {
+			CodeMirror = window.CodeMirror;
+		}
+		CodeMirror.defineMode(modeName, () => CMMode);
+		CodeMirror.registerHelper('hint', modeName, CMHints);
+	}
+
+	function addTheme(theme) {
+		themes.push(theme);
+	}
+
+	class SequenceDiagram extends EventObject {
+		constructor(code = null, options = {}) {
+			super();
+
+			if(code && typeof code === 'object') {
+				options = code;
+				code = options.code;
+			}
+
+			this.registerCodeMirrorMode = registerCodeMirrorMode;
+
+			this.code = code;
+			this.parser = SharedParser;
+			this.generator = SharedGenerator;
+			this.renderer = new Renderer(Object.assign({themes}, options));
+			this.exporter = new Exporter();
+			this.renderer.addEventForwarding(this);
+			if(options.container) {
+				options.container.appendChild(this.dom());
+			}
+			if(typeof this.code === 'string') {
+				this.render();
+			}
+		}
+
+		clone(options = {}) {
+			return new SequenceDiagram(Object.assign({
+				code: this.code,
+				container: null,
+				themes: this.renderer.getThemes(),
+				namespace: null,
+				components: this.renderer.components,
+				SVGTextBlockClass: this.renderer.SVGTextBlockClass,
+			}, options));
+		}
+
+		set(code = '') {
+			if(this.code === code) {
+				return;
+			}
+
+			this.code = code;
+			this.render();
+		}
+
+		process(code) {
+			const parsed = this.parser.parse(code);
+			return this.generator.generate(parsed);
+		}
+
+		addTheme(theme) {
+			this.renderer.addTheme(theme);
+		}
+
+		setHighlight(line = null) {
+			this.renderer.setHighlight(line);
+		}
+
+		getThemeNames() {
+			return this.renderer.getThemeNames();
+		}
+
+		getThemes() {
+			return this.renderer.getThemes();
+		}
+
+		getSVGSynchronous() {
+			return this.exporter.getSVGURL(this.renderer);
+		}
+
+		getSVG() {
+			return Promise.resolve({
+				url: this.getSVGSynchronous(),
+				latest: true,
+			});
+		}
+
+		getPNG({resolution = 1, size = null} = {}) {
+			if(size) {
+				this.renderer.width = size.width;
+				this.renderer.height = size.height;
+			}
+			return new Promise((resolve) => {
+				this.exporter.getPNGURL(
+					this.renderer,
+					resolution,
+					(url, latest) => {
+						resolve({url, latest});
+					}
+				);
+			});
+		}
+
+		getSize() {
+			return {
+				width: this.renderer.width,
+				height: this.renderer.height,
+			};
+		}
+
+		render(processed = null) {
+			const dom = this.renderer.svg();
+			const originalParent = dom.parentNode;
+			if(!document.body.contains(dom)) {
+				if(originalParent) {
+					originalParent.removeChild(dom);
+				}
+				document.body.appendChild(dom);
+			}
+			try {
+				if(!processed) {
+					processed = this.process(this.code);
+				}
+				this.renderer.render(processed);
+			} finally {
+				if(dom.parentNode !== originalParent) {
+					document.body.removeChild(dom);
+					if(originalParent) {
+						originalParent.appendChild(dom);
+					}
+				}
+			}
+		}
+
+		setContainer(node = null) {
+			const dom = this.dom();
+			if(dom.parentNode) {
+				dom.parentNode.removeChild(dom);
+			}
+			if(node) {
+				node.appendChild(dom);
+			}
+		}
+
+		dom() {
+			return this.renderer.svg();
+		}
+	}
+
+	function convert(element, code = null, options = {}) {
+		if(code === null) {
+			code = element.innerText;
+		} else if(typeof code === 'object') {
+			options = code;
+			code = options.code;
+		}
+		const diagram = new SequenceDiagram(code, options);
+		element.parentNode.insertBefore(diagram.dom(), element);
+		element.parentNode.removeChild(element);
+		return diagram;
+	}
+
+	function convertAll(root = null) {
+		if(!root) {
+			root = document;
+		}
+		const elements = root.getElementsByClassName('sequence-diagram');
+		for(let i = 0; i < elements.length; ++ i) {
+			convert(elements[i]);
+		}
+	}
+
+	return Object.assign(SequenceDiagram, {
+		Parser,
+		Generator,
+		Renderer,
+		Exporter,
+		themes,
+		addTheme,
+		registerCodeMirrorMode,
+		convert,
+		convertAll,
+	});
+});
diff --git a/scripts/sequence/sequence_integration_spec.js b/scripts/sequence/SequenceDiagram_spec.js
similarity index 66%
rename from scripts/sequence/sequence_integration_spec.js
rename to scripts/sequence/SequenceDiagram_spec.js
index 722bc06..8020f63 100644
--- a/scripts/sequence/sequence_integration_spec.js
+++ b/scripts/sequence/SequenceDiagram_spec.js
@@ -1,53 +1,53 @@
 /* jshint -W072 */ // Allow several required modules
-defineDescribe('Sequence Integration', [
+defineDescribe('SequenceDiagram', [
+	'./SequenceDiagram',
 	'./Parser',
 	'./Generator',
 	'./Renderer',
-	'./themes/Basic',
+	'./Exporter',
 	'stubs/SVGTextBlock',
 ], (
+	SequenceDiagram,
 	Parser,
 	Generator,
 	Renderer,
-	BasicTheme,
+	Exporter,
 	SVGTextBlock
 ) => {
 	/* jshint +W072 */
 	'use strict';
 
-	let parser = null;
-	let generator = null;
-	let renderer = null;
-	let theme = null;
-
-	beforeEach(() => {
-		theme = new BasicTheme();
-		parser = new Parser();
-		generator = new Generator();
-		renderer = new Renderer({
-			themes: [new BasicTheme()],
-			namespace: '',
-			SVGTextBlockClass: SVGTextBlock,
-		});
-		document.body.appendChild(renderer.svg());
-	});
-
-	afterEach(() => {
-		document.body.removeChild(renderer.svg());
-	});
-
-	function getSimplifiedContent(r) {
-		return (r.svg().outerHTML
+	function getSimplifiedContent(d) {
+		return (d.dom().outerHTML
 			.replace(/<g><\/g>/g, '')
 			.replace(' xmlns="http://www.w3.org/2000/svg" version="1.1"', '')
 		);
 	}
 
-	it('Renders empty diagrams without error', () => {
-		const parsed = parser.parse('');
-		const sequence = generator.generate(parsed);
-		renderer.render(sequence);
-		expect(getSimplifiedContent(renderer)).toEqual(
+	let diagram = null;
+
+	beforeEach(() => {
+		diagram = new SequenceDiagram({
+			namespace: '',
+			SVGTextBlockClass: SVGTextBlock,
+		});
+	});
+
+	it('contains references to core objects', () => {
+		expect(SequenceDiagram.Parser).toBe(Parser);
+		expect(SequenceDiagram.Generator).toBe(Generator);
+		expect(SequenceDiagram.Renderer).toBe(Renderer);
+		expect(SequenceDiagram.Exporter).toBe(Exporter);
+	});
+
+	it('provides default themes', () => {
+		expect(SequenceDiagram.themes.length).toEqual(2);
+	});
+
+	it('renders empty diagrams without error', () => {
+		diagram.set('');
+
+		expect(getSimplifiedContent(diagram)).toEqual(
 			'<svg viewBox="-5 -5 10 10">' +
 			'<defs>' +
 			'<mask id="LineMask" maskUnits="userSpaceOnUse">' +
@@ -60,12 +60,10 @@ defineDescribe('Sequence Integration', [
 		);
 	});
 
-	it('Renders simple metadata', () => {
-		const parsed = parser.parse('title My title here');
-		const sequence = generator.generate(parsed);
-		renderer.render(sequence);
+	it('renders simple metadata', () => {
+		diagram.set('title My title here');
 
-		expect(getSimplifiedContent(renderer)).toEqual(
+		expect(getSimplifiedContent(diagram)).toEqual(
 			'<svg viewBox="-11.5 -16 23 21">' +
 			'<defs>' +
 			'<mask id="LineMask" maskUnits="userSpaceOnUse">' +
@@ -86,12 +84,11 @@ defineDescribe('Sequence Integration', [
 		);
 	});
 
-	it('Renders simple components', () => {
-		const parsed = parser.parse('A -> B');
-		const sequence = generator.generate(parsed);
-		renderer.render(sequence);
+	it('renders simple components', () => {
+		diagram.set('A -> B');
+
+		const content = getSimplifiedContent(diagram);
 
-		const content = getSimplifiedContent(renderer);
 		expect(content).toContain(
 			'<svg viewBox="-5 -5 82 56">'
 		);
@@ -149,9 +146,7 @@ defineDescribe('Sequence Integration', [
 		.then(findSamples)
 		.then((samples) => samples.forEach((code, i) => {
 			it('Renders readme example #' + (i + 1) + ' without error', () => {
-				const parsed = parser.parse(code);
-				const sequence = generator.generate(parsed);
-				expect(() => renderer.render(sequence)).not.toThrow();
+				expect(() => diagram.set(code)).not.toThrow();
 			});
 		}))
 	);
diff --git a/scripts/specs.js b/scripts/specs.js
index c3a85e7..834d297 100644
--- a/scripts/specs.js
+++ b/scripts/specs.js
@@ -5,6 +5,7 @@ define([
 	'svg/SVGTextBlock_spec',
 	'svg/SVGShapes_spec',
 	'interface/Interface_spec',
+	'sequence/SequenceDiagram_spec',
 	'sequence/Tokeniser_spec',
 	'sequence/Parser_spec',
 	'sequence/LabelPatternParser_spec',
@@ -19,5 +20,4 @@ define([
 	'sequence/components/Marker_spec',
 	'sequence/components/Note_spec',
 	'sequence/components/Parallel_spec',
-	'sequence/sequence_integration_spec',
 ]);
diff --git a/scripts/tester/jshintRunner.js b/scripts/tester/jshintRunner.js
index a3331ac..f1aa7d7 100644
--- a/scripts/tester/jshintRunner.js
+++ b/scripts/tester/jshintRunner.js
@@ -8,6 +8,7 @@ define(['jshintConfig', 'specs'], (jshintConfig) => {
 	const extraFiles = [
 		'scripts/main.js',
 		'scripts/requireConfig.js',
+		'scripts/readmeImages.js',
 	];
 
 	const PREDEF = [
diff --git a/styles/readme_images.css b/styles/readmeImages.css
similarity index 100%
rename from styles/readme_images.css
rename to styles/readmeImages.css