diff --git a/README.md b/README.md
index 27afa0c..2218c63 100644
--- a/README.md
+++ b/README.md
@@ -25,7 +25,7 @@ A ROM patcher made in Javascript.
 Modders and hackers can embed Rom Patcher JS in their websites to provide an online ROM patcher for their patches, allowing users to patch ROMs without downloading any files.<br/>
 
 - File [`index_template.html`](https://github.com/marcrobledo/RomPatcher.js/blob/master/index_template.html) includes a simple working example
-- Read [the wiki](https://github.com/marcrobledo/RomPatcher.js/wiki) for more detailed instructions
+- Read [the wiki](https://github.com/marcrobledo/RomPatcher.js/wiki/Embedding-Rom-Patcher-JS) for more detailed instructions
 
 
 &nbsp;
@@ -36,7 +36,7 @@ Install dependencies:
 Patch a ROM:
 > node index.js patch "my_rom.bin" "my_patch.ips"
 
-Create a patch:
+Create an IPS patch:
 > node index.js create "original_rom.bin" modified_rom.bin"
 
 Show all options:
diff --git a/_cache_service_worker.js b/_cache_service_worker.js
index b58c103..5585263 100644
--- a/_cache_service_worker.js
+++ b/_cache_service_worker.js
@@ -6,7 +6,7 @@
 */
 
 var PRECACHE_ID = 'rom-patcher-js';
-var PRECACHE_VERSION = 'v30beta1b';
+var PRECACHE_VERSION = 'v30rc1';
 var PRECACHE_URLS = [
 	'/RomPatcher.js/', '/RomPatcher.js/index.html',
 	'/RomPatcher.js/manifest.json',
diff --git a/index.html b/index.html
index 7550696..153938d 100644
--- a/index.html
+++ b/index.html
@@ -34,21 +34,6 @@
 
 	<link type="text/css" rel="stylesheet" href="./webapp/style.css" media="all"/>
 
-
-
-	<script type="text/javascript" src="./rom-patcher-js/modules/BinFile.js"></script>
-	<script type="text/javascript" src="./rom-patcher-js/modules/HashCalculator.js"></script>
-	<script type="text/javascript" src="./rom-patcher-js/modules/RomPatcher.format.ips.js"></script>
-	<script type="text/javascript" src="./rom-patcher-js/modules/RomPatcher.format.ups.js"></script>
-	<script type="text/javascript" src="./rom-patcher-js/modules/RomPatcher.format.aps_n64.js"></script>
-	<script type="text/javascript" src="./rom-patcher-js/modules/RomPatcher.format.aps_gba.js"></script>
-	<script type="text/javascript" src="./rom-patcher-js/modules/RomPatcher.format.bps.js"></script>
-	<script type="text/javascript" src="./rom-patcher-js/modules/RomPatcher.format.rup.js"></script>
-	<script type="text/javascript" src="./rom-patcher-js/modules/RomPatcher.format.ppf.js"></script>
-	<script type="text/javascript" src="./rom-patcher-js/modules/RomPatcher.format.pmsr.js"></script>
-	<script type="text/javascript" src="./rom-patcher-js/modules/RomPatcher.format.vcdiff.js"></script>
-	<script type="text/javascript" src="./rom-patcher-js/modules/zip.js/zip.min.js"></script>
-	<script type="text/javascript" src="./rom-patcher-js/RomPatcher.js"></script>
 	<script type="text/javascript" src="./rom-patcher-js/RomPatcher.webapp.js"></script>
 	<script type="text/javascript" src="./webapp/webapp.js"></script>
 </head>
@@ -67,7 +52,7 @@
 			<div class="row m-b" id="rom-patcher-row-file-rom">
 				<div class="text-right"><label for="rom-patcher-input-file-rom" data-localize="yes">ROM file:</label></div>
 				<div class="rom-patcher-container-input">
-					<input type="file" id="rom-patcher-input-file-rom" class="w100 empty" />
+					<input type="file" id="rom-patcher-input-file-rom" class="empty" disabled />
 				</div>
 			</div>
 			<div class="row m-b" id="rom-patcher-row-alter-header">
@@ -98,7 +83,7 @@
 			<div class="row m-b" id="rom-patcher-row-file-patch">
 				<div class="text-right"><label for="rom-patcher-input-file-patch" data-localize="yes">Patch file:</label></div>
 				<div class="rom-patcher-container-input">
-					<input type="file" id="rom-patcher-input-file-patch" class="w100 empty" accept=".ips,.ups,.bps,.aps,.rup,.ppf,.mod,.xdelta,.vcdiff,.zip" />
+					<input type="file" id="rom-patcher-input-file-patch" class="empty" accept=".ips,.ups,.bps,.aps,.rup,.ppf,.mod,.xdelta,.vcdiff,.zip" disabled />
 				</div>
 			</div>
 			<div class="row m-b" id="rom-patcher-row-patch-description">
@@ -120,21 +105,21 @@
 			<div class="row m-b">
 				<div class="text-right"><label for="patch-builder-input-file-original" data-localize="yes" >Original ROM:</label></div>
 				<div>
-					<input type="file" id="patch-builder-input-file-original" class="w100 empty" />
+					<input type="file" id="patch-builder-input-file-original" class="empty" disabled />
 				</div>
 			</div>
 
 			<div class="row m-b">
 				<div class="text-right"><label for="patch-builder-input-file-modified" data-localize="yes">Modified ROM:</label></div>
 				<div>
-					<input type="file" id="patch-builder-input-file-modified" class="w100 empty" />
+					<input type="file" id="patch-builder-input-file-modified" class="empty" disabled />
 				</div>
 			</div>
 
 			<div class="row m-b">
 				<div class="text-right"><label for="patch-builder-select-patch-type" data-localize="yes">Patch type:</label></div>
 				<div>
-					<select id="patch-builder-select-patch-type">
+					<select id="patch-builder-select-patch-type" disabled>
 						<option value="ips">IPS</option>
 						<option value="bps">BPS</option>
 						<option value="ppf">PPF</option>
@@ -147,7 +132,7 @@
 
 			<div class="buttons text-center">
 				<div id="patch-builder-row-error-message" class="m-b"><span id="patch-builder-error-message"></span></div>
-				<button id="patch-builder-button-create" disabled data-localize="yes">Create patch</button>
+				<button id="patch-builder-button-create" disabled data-localize="yes" disabled>Create patch</button>
 			</div>
 		</div>
 	</div>
@@ -166,7 +151,7 @@
 		<button id="button-settings" class="btn-transparent"><img src="./webapp/icon_settings.svg" loading="lazy" class="icon settings" /> <span data-localize="yes">Settings</span></button>
 	</div>
 
-	Rom Patcher JS <small>v3.0 <a style="color:rgb(255, 197, 7)" href="legacy/" rel="nofollow">Beta 1</a></small> by <a href="/">Marc Robledo</a>
+	Rom Patcher JS <small>v3.0 <a style="color:rgb(255, 197, 7)" href="legacy/" rel="nofollow">RC1</a></small> by <a href="/">Marc Robledo</a>
 	<br />
 	<img src="./webapp/icon_github.svg" loading="lazy" class="icon github" /> <a href="https://github.com/marcrobledo/RomPatcher.js/" target="_blank">See on GitHub</a>
 	<img src="./webapp/icon_heart.svg" loading="lazy" class="icon heart" /> <a href="https://www.paypal.me/marcrobledo/5" target="_blank" rel="nofollow">Donate</a>
diff --git a/index_template.html b/index_template.html
index 2613e1a..eb308c6 100644
--- a/index_template.html
+++ b/index_template.html
@@ -10,22 +10,9 @@
 
 	<!-- Rom Patcher JS needed CSS/JS files -->
 	<link type="text/css" rel="stylesheet" href="./rom-patcher-js/style.css" media="all" />
-	<script type="text/javascript" src="./rom-patcher-js/modules/BinFile.js"></script>
-	<script type="text/javascript" src="./rom-patcher-js/modules/HashCalculator.js"></script>
-	<script type="text/javascript" src="./rom-patcher-js/modules/RomPatcher.format.ips.js"></script>
-	<script type="text/javascript" src="./rom-patcher-js/modules/RomPatcher.format.ups.js"></script>
-	<script type="text/javascript" src="./rom-patcher-js/modules/RomPatcher.format.aps_n64.js"></script>
-	<script type="text/javascript" src="./rom-patcher-js/modules/RomPatcher.format.aps_gba.js"></script>
-	<script type="text/javascript" src="./rom-patcher-js/modules/RomPatcher.format.bps.js"></script>
-	<script type="text/javascript" src="./rom-patcher-js/modules/RomPatcher.format.rup.js"></script>
-	<script type="text/javascript" src="./rom-patcher-js/modules/RomPatcher.format.ppf.js"></script>
-	<script type="text/javascript" src="./rom-patcher-js/modules/RomPatcher.format.pmsr.js"></script>
-	<script type="text/javascript" src="./rom-patcher-js/modules/RomPatcher.format.vcdiff.js"></script>
-	<script type="text/javascript" src="./rom-patcher-js/modules/zip.js/zip.min.js"></script>
-	<script type="text/javascript" src="./rom-patcher-js/RomPatcher.js"></script>
 	<script type="text/javascript" src="./rom-patcher-js/RomPatcher.webapp.js"></script>
 
-	<!-- Rom Patcher JS initizlization -->
+	<!-- Rom Patcher JS initialization -->
 	<script type="text/javascript">
 		window.addEventListener('load', function (evt) {
 			try {
@@ -60,17 +47,17 @@
 
 	<!-- Rom Patcher JS container -->
 	<!--
-			The following elements are required for Rom Patcher JS to work:
-				#rom-patcher-input-file-rom
-				#rom-patcher-input-file-patch
-				#rom-patcher-button-apply
-			The rest of elements are informative and can be removed, though it's recommended to keep them for a better user experience.
-		-->
+		The following elements are required for Rom Patcher JS to work:
+			#rom-patcher-input-file-rom
+			#rom-patcher-input-file-patch
+			#rom-patcher-button-apply
+		The rest of elements are informative and can be removed, though it's recommended to keep them for a better user experience.
+	-->
 	<div id="rom-patcher-container">
 		<div class="rom-patcher-row margin-bottom" id="rom-patcher-row-file-rom">
 			<div class="text-right"><label for="rom-patcher-input-file-rom" data-localize="yes">ROM file:</label></div>
 			<div class="rom-patcher-container-input">
-				<input type="file" id="rom-patcher-input-file-rom" class="empty" />
+				<input type="file" id="rom-patcher-input-file-rom" class="empty" disabled />
 			</div>
 		</div>
 		<div class="margin-bottom text-selectable text-mono text-muted" id="rom-patcher-rom-info">
@@ -97,7 +84,7 @@
 			</div>
 			<div class="rom-patcher-container-input">
 				<input type="file" id="rom-patcher-input-file-patch" class="empty"
-					accept=".ips,.ups,.bps,.aps,.rup,.ppf,.mod,.xdelta,.vcdiff,.zip" />
+					accept=".ips,.ups,.bps,.aps,.rup,.ppf,.mod,.xdelta,.vcdiff,.zip" disabled />
 			</div>
 		</div>
 		<div class="rom-patcher-row margin-bottom" id="rom-patcher-row-patch-description">
diff --git a/rom-patcher-js/RomPatcher.webapp.js b/rom-patcher-js/RomPatcher.webapp.js
index 80e89be..5141265 100644
--- a/rom-patcher-js/RomPatcher.webapp.js
+++ b/rom-patcher-js/RomPatcher.webapp.js
@@ -31,14 +31,29 @@
 
 /*
 	to-do list:
-	- load JS modules dynamically when RomPatchwerWeb is initialized
-	- allow multiple instances of RomPatcherWeb
+	- allow multiple instances of RomPatcherWeb?
 	- switch to ES6 classes and modules?
 */
 
 const ROM_PATCHER_JS_PATH = './rom-patcher-js/';
 
 var RomPatcherWeb = (function () {
+	const SCRIPT_DEPENDENCIES = [
+		'modules/BinFile.js',
+		'modules/HashCalculator.js',
+		'modules/RomPatcher.format.ips.js',
+		'modules/RomPatcher.format.ups.js',
+		'modules/RomPatcher.format.aps_n64.js',
+		'modules/RomPatcher.format.aps_gba.js',
+		'modules/RomPatcher.format.bps.js',
+		'modules/RomPatcher.format.rup.js',
+		'modules/RomPatcher.format.ppf.js',
+		'modules/RomPatcher.format.pmsr.js',
+		'modules/RomPatcher.format.vcdiff.js',
+		'modules/zip.js/zip.min.js',
+		'RomPatcher.js'
+	];
+
 	const WEB_CRYPTO_AVAILABLE = window.crypto && window.crypto.subtle && window.crypto.subtle.digest;
 	const settings = {
 		language: typeof navigator.language === 'string' ? navigator.language.substring(0, 2) : 'en',
@@ -49,6 +64,7 @@ var RomPatcherWeb = (function () {
 
 		onloadrom: null,
 		onvalidaterom: null,
+		onloadpatch: null,
 		onpatch: null
 	};
 	var romFile, patch;
@@ -384,10 +400,6 @@ var RomPatcherWeb = (function () {
 	webWorkerCrc.onerror = event => { // listen for events from the worker
 		_setToastError('webWorkerCrc error: ' + event.message);
 	};
-	/* zip-js web worker */
-	zip.useWebWorkers = true;
-	zip.workerScriptsPath = ROM_PATCHER_JS_PATH + 'modules/zip.js/';
-
 
 	const _getChecksumStartOffset = function () {
 		if (romFile) {
@@ -402,12 +414,177 @@ var RomPatcherWeb = (function () {
 	}
 
 
+	const _getScriptPath = function () {
+		const currentScripts = document.querySelectorAll('script');
+		var scriptPath;
+		if (document.currentScript) {
+			scriptPath = document.currentScript.src;
+		} else {
+			for (var i = 0; i < currentScripts.length; i++) {
+				if (currentScripts[i].src.indexOf('RomPatcher.webapp.js') !== -1) {
+					scriptPath = currentScripts[i].src;
+					break;
+				}
+			}
+			if (!scriptPath)
+				scriptPath = './rom-patcher-js/';
+		}
+		return scriptPath.substring(0, scriptPath.lastIndexOf('/') + 1);
+	}
+	const _getMissingDependencies = function () {
+		const currentScripts = document.querySelectorAll('script');
+		const scriptPath = _getScriptPath();
+		var missingDependencies = [];
+		for (var i = 0; i < SCRIPT_DEPENDENCIES.length && !isLoaded; i++) {
+			var isLoaded = false;
+			for (var j = 0; j < currentScripts.length; j++) {
+				if (currentScripts[j].src === scriptPath + SCRIPT_DEPENDENCIES[i])
+					isLoaded = true;
+			}
+			if (!isLoaded)
+				missingDependencies.push(scriptPath + SCRIPT_DEPENDENCIES[i]);
+		}
+
+		return missingDependencies;
+	}
+	const _initialize = function (newSettings, embededPatchInfo) {
+		/* embeded patches */
+		var validEmbededPatch = false;
+		if (embededPatchInfo) {
+			if (typeof embededPatchInfo === 'string')
+				embededPatchInfo = { file: embededPatchInfo };
+
+			if (typeof embededPatchInfo === 'object') {
+				if (typeof embededPatchInfo.file === 'string') {
+					validEmbededPatch = true;
+				} else {
+					throw new Error('Rom Patcher JS: invalid embeded patch file');
+				}
+			}
+		}
+
+
+
+		/* check if Rom Patcher JS core is available */
+		if (typeof RomPatcher !== 'object') {
+			throw new Error('Rom Patcher JS: core not found');
+		}
+
+
+
+		/* check if zip-js web worker is available */
+		if (typeof zip !== 'object' || typeof zip.useWebWorkers !== 'boolean') {
+			throw new Error('Rom Patcher JS: zip.js web worker not found');
+		}
+		zip.useWebWorkers = true;
+		zip.workerScriptsPath = ROM_PATCHER_JS_PATH + 'modules/zip.js/';
+
+		/* check if all required HTML elements are in DOM */
+		const htmlInputFileRom = htmlElements.get('input-file-rom');
+		if (htmlInputFileRom && htmlInputFileRom.tagName === 'INPUT' && htmlInputFileRom.type === 'file') {
+			htmlInputFileRom.addEventListener('change', function (evt) {
+				htmlElements.disableAll();
+				new BinFile(this, RomPatcherWeb.provideRomFile);
+			});
+		} else {
+			throw new Error('Rom Patcher JS: input#rom-patcher-input-file-rom[type=file] not found');
+		}
+		const htmlInputFilePatch = htmlElements.get('input-file-patch');
+		if (htmlInputFilePatch && htmlInputFilePatch.tagName === 'INPUT' && htmlInputFilePatch.type === 'file') {
+			htmlInputFilePatch.addEventListener('change', function (evt) {
+				htmlElements.disableAll();
+				new BinFile(this, RomPatcherWeb.providePatchFile);
+			});
+		} else {
+			throw new Error('Rom Patcher JS: input#rom-patcher-input-file-patch[type=file] not found');
+		}
+		const htmlButtonApply = htmlElements.get('button-apply');
+		if (htmlButtonApply && htmlButtonApply.tagName === 'BUTTON') {
+			htmlButtonApply.addEventListener('click', RomPatcherWeb.applyPatch);
+		} else {
+			throw new Error('Rom Patcher JS: button#rom-patcher-button-apply not found');
+		}
+		const htmlCheckboxAlterHeader = htmlElements.get('checkbox-alter-header');
+		if (htmlCheckboxAlterHeader && htmlCheckboxAlterHeader.tagName === 'INPUT' && htmlCheckboxAlterHeader.type === 'checkbox') {
+			htmlCheckboxAlterHeader.addEventListener('change', function (evt) {
+				if (!romFile)
+					return false;
+
+				const headerInfo = RomPatcher.isRomHeadered(romFile);
+				if (headerInfo) {
+					htmlElements.disableAll();
+					webWorkerCrc.postMessage({ u8array: romFile._u8array, fileName: romFile.fileName, checksumStartOffset: _getChecksumStartOffset() }, [romFile._u8array.buffer]);
+				}
+			});
+		}
+		/* set all default input status just in case HTML is wrong */
+		htmlElements.disableAll();
+		/* reset input files */
+		htmlElements.setValue('input-file-rom', '');
+		htmlElements.setValue('input-file-patch', '');
+
+
+		/* translatable elements */
+		const translatableElements = document.querySelectorAll('*[data-localize="yes"]');
+		for (var i = 0; i < translatableElements.length; i++) {
+			translatableElements[i].setAttribute('data-localize', translatableElements[i].innerHTML);
+		}
+
+		/* add drag and drop events */
+		if (newSettings && newSettings.allowDropFiles) {
+			window.addEventListener('dragover', function (evt) {
+				if (_dragEventContainsFiles(evt))
+					evt.preventDefault(); /* needed ! */
+			});
+			window.addEventListener('drop', function (evt) {
+				evt.preventDefault();
+				if (_dragEventContainsFiles(evt)) {
+					const droppedFiles = evt.dataTransfer.files;
+					if (droppedFiles && droppedFiles.length === 1) {
+						new BinFile(droppedFiles[0], function (binFile) {
+							if (RomPatcherWeb.getEmbededPatches()) {
+								RomPatcherWeb.provideRomFile(binFile, true);
+							} else if (ZIPManager.isZipFile(binFile)) {
+								ZIPManager.unzipAny(binFile._u8array.buffer);
+							} else if (RomPatcher.parsePatchFile(binFile)) {
+								RomPatcherWeb.providePatchFile(binFile, null, true);
+							} else {
+								RomPatcherWeb.provideRomFile(binFile, true);
+							}
+						});
+					}
+				}
+			});
+			htmlInputFileRom.addEventListener('drop', function (evt) {
+				evt.stopPropagation();
+			});
+			htmlInputFilePatch.addEventListener('drop', function (evt) {
+				evt.stopPropagation();
+			});
+		}
+
+		console.log('Rom Patcher JS initialized');
+		initialized = true;
+
+
+		/* initialize Rom Patcher */
+		RomPatcherWeb.setSettings(newSettings);
+
+		/* download embeded patch */
+		if (validEmbededPatch)
+			_fetchPatchFile(embededPatchInfo);
+		else
+			htmlElements.enableAll();
+	}
+
+
 
 	/* localization */
 	const _ = function (str) { return ROM_PATCHER_LOCALE[settings.language] && ROM_PATCHER_LOCALE[settings.language][str] ? ROM_PATCHER_LOCALE[settings.language][str] : str };
 
 
 	var initialized = false;
+	var loading = 0;
 	return {
 		_: function (str) { /* public localization function for external usage purposes */
 			return _(str);
@@ -562,10 +739,14 @@ var RomPatcherWeb = (function () {
 
 						RomPatcherWeb.validateCurrentRom(_getChecksumStartOffset());
 
+						if (typeof settings.onloadpatch === 'function') {
+							settings.onloadpatch(binFile, embededPatchInfo, parsedPatch);
+						}
+
 						if (transferFakeFile) {
 							htmlElements.setFakeFile('input-file-patch', binFile.fileName);
 						}
-					}else{
+					} else {
 						_setToastError(_('Invalid patch file'));
 					}
 				}
@@ -606,21 +787,9 @@ var RomPatcherWeb = (function () {
 		initialize: function (newSettings, embededPatchInfo) {
 			if (initialized)
 				throw new Error('Rom Patcher JS was already initialized');
+			else if (loading)
+				throw new Error('Rom Patcher JS is already loading or has failed to load');
 
-			/* embeded patches */
-			var validEmbededPatch = false;
-			if (embededPatchInfo) {
-				if (typeof embededPatchInfo === 'string')
-					embededPatchInfo = { file: embededPatchInfo };
-
-				if (typeof embededPatchInfo === 'object') {
-					if (typeof embededPatchInfo.file === 'string') {
-						validEmbededPatch = true;
-					} else {
-						throw new Error('Rom Patcher JS: invalid embeded patch file');
-					}
-				}
-			}
 
 			/* check incompatible browsers */
 			if (
@@ -633,101 +802,32 @@ var RomPatcherWeb = (function () {
 				throw new Error('Rom Patcher JS: incompatible browser');
 
 
-
-			/* check if all required HTML elements are in DOM */
-			const htmlInputFileRom = htmlElements.get('input-file-rom');
-			if (htmlInputFileRom && htmlInputFileRom.tagName === 'INPUT' && htmlInputFileRom.type === 'file') {
-				htmlInputFileRom.addEventListener('change', function (evt) {
-					htmlElements.disableAll();
-					new BinFile(this, RomPatcherWeb.provideRomFile);
-				});
-			} else {
-				throw new Error('Rom Patcher JS: input#rom-patcher-input-file-rom[type=file] not found');
-			}
-			const htmlInputFilePatch = htmlElements.get('input-file-patch');
-			if (htmlInputFilePatch && htmlInputFilePatch.tagName === 'INPUT' && htmlInputFilePatch.type === 'file') {
-				htmlInputFilePatch.addEventListener('change', function (evt) {
-					htmlElements.disableAll();
-					new BinFile(this, RomPatcherWeb.providePatchFile);
-				});
-			} else {
-				throw new Error('Rom Patcher JS: input#rom-patcher-input-file-patch[type=file] not found');
-			}
-			const htmlButtonApply = htmlElements.get('button-apply');
-			if (htmlButtonApply && htmlButtonApply.tagName === 'BUTTON') {
-				htmlButtonApply.addEventListener('click', RomPatcherWeb.applyPatch);
-			} else {
-				throw new Error('Rom Patcher JS: button#rom-patcher-button-apply not found');
-			}
-			const htmlCheckboxAlterHeader = htmlElements.get('checkbox-alter-header');
-			if (htmlCheckboxAlterHeader && htmlCheckboxAlterHeader.tagName === 'INPUT' && htmlCheckboxAlterHeader.type === 'checkbox') {
-				htmlCheckboxAlterHeader.addEventListener('change', function (evt) {
-					if (!romFile)
-						return false;
-
-					const headerInfo = RomPatcher.isRomHeadered(romFile);
-					if (headerInfo) {
+			/* queue script dependencies */
+			const missingDependencies = _getMissingDependencies();
+			loading = missingDependencies.length;
+			const onLoadScript = function () {
+				loading--;
+				if (loading === 0) {
+					try {
+						_initialize(newSettings, embededPatchInfo);
+					} catch (ex) {
+						_setToastError(ex.message);
 						htmlElements.disableAll();
-						webWorkerCrc.postMessage({ u8array: romFile._u8array, fileName: romFile.fileName, checksumStartOffset: _getChecksumStartOffset() }, [romFile._u8array.buffer]);
 					}
-				});
-			}
-			/* set all default input status just in case HTML is wrong */
-			htmlElements.setEnabled('button-apply', false);
-			/* reset input files */
-			htmlElements.setValue('input-file-rom', '');
-			htmlElements.setValue('input-file-patch', '');
+				}
+			};
+			const onErrorScript = function () {
+				throw new Error('Rom Patcher JS: error loading script ' + script.src);
+			};
+			console.log('Rom Patcher JS: loading ' + missingDependencies.length + ' dependencies');
+			missingDependencies.forEach(function (path) {
+				var script = document.createElement('script');
+				script.onload = onLoadScript;
+				script.onerror = onErrorScript;
+				script.src = path;
 
-
-			/* translatable elements */
-			const translatableElements = document.querySelectorAll('*[data-localize="yes"]');
-			for (var i = 0; i < translatableElements.length; i++) {
-				translatableElements[i].setAttribute('data-localize', translatableElements[i].innerHTML);
-			}
-
-			/* add drag and drop events */
-			if (newSettings && newSettings.allowDropFiles) {
-				window.addEventListener('dragover', function (evt) {
-					if (_dragEventContainsFiles(evt))
-						evt.preventDefault(); /* needed ! */
-				});
-				window.addEventListener('drop', function (evt) {
-					evt.preventDefault();
-					if (_dragEventContainsFiles(evt)) {
-						const droppedFiles = evt.dataTransfer.files;
-						if (droppedFiles && droppedFiles.length === 1) {
-							new BinFile(droppedFiles[0], function (binFile) {
-								if (RomPatcherWeb.getEmbededPatches()) {
-									RomPatcherWeb.provideRomFile(binFile, true);
-								} else if (ZIPManager.isZipFile(binFile)) {
-									ZIPManager.unzipAny(binFile._u8array.buffer);
-								} else if (RomPatcher.parsePatchFile(binFile)) {
-									RomPatcherWeb.providePatchFile(binFile, null, true);
-								} else {
-									RomPatcherWeb.provideRomFile(binFile, true);
-								}
-							});
-						}
-					}
-				});
-				htmlInputFileRom.addEventListener('drop', function (evt) {
-					evt.stopPropagation();
-				});
-				htmlInputFilePatch.addEventListener('drop', function (evt) {
-					evt.stopPropagation();
-				});
-			}
-
-			console.log('Rom Patcher JS initialized');
-			initialized = true;
-
-
-			/* initialize Rom Patcher */
-			RomPatcherWeb.setSettings(newSettings);
-
-			/* download embeded patch */
-			if (validEmbededPatch)
-				_fetchPatchFile(embededPatchInfo);
+				document.head.appendChild(script);
+			});
 		},
 
 		applyPatch: function () {
@@ -859,6 +959,11 @@ var RomPatcherWeb = (function () {
 				else if (typeof newSettings.onvalidaterom !== 'undefined')
 					settings.onvalidaterom = null;
 
+				if (typeof newSettings.onloadpatch === 'function')
+					settings.onloadpatch = newSettings.onloadpatch;
+				else if (typeof newSettings.onloadpatch !== 'undefined')
+					settings.onloadpatch = null;
+
 				if (typeof newSettings.onpatch === 'function')
 					settings.onpatch = newSettings.onpatch;
 				else if (typeof newSettings.onpatch !== 'undefined')
@@ -935,11 +1040,11 @@ const ZIPManager = (function (romPatcherWeb) {
 
 	const _unzipEntry = function (zippedEntry, onUnzip) {
 		htmlElements.disableAll();
-		if (onUnzip === RomPatcherWeb.provideRomFile) {
+		if (onUnzip === romPatcherWeb.provideRomFile) {
 			_setRomInputSpinner(true);
-		} else if (onUnzip === RomPatcherWeb.providePatchFile) {
+		} else if (onUnzip === romPatcherWeb.providePatchFile) {
 			_setPatchInputSpinner(true);
-		}else{
+		} else {
 			throw new Error('ZIPManager._unzipEntry: invalid onUnzip callback');
 		}
 		zippedEntry.getData(new zip.BlobWriter(), function (blob) {
@@ -949,7 +1054,7 @@ const ZIPManager = (function (romPatcherWeb) {
 				binFile.fileName = zippedEntry.filename;
 
 				/* transfer files to input elements */
-				if (onUnzip === RomPatcherWeb.provideRomFile) {
+				if (onUnzip === romPatcherWeb.provideRomFile) {
 					_setRomInputSpinner(false);
 					onUnzip(binFile, true);
 				} else {
@@ -963,19 +1068,19 @@ const ZIPManager = (function (romPatcherWeb) {
 
 	const _showFilePicker = function (zipEntries, onUnzip) {
 		const _evtClickEntry = function (evt) {
-			if(typeof dialogZip.close === 'function'){
+			if (typeof dialogZip.close === 'function') {
 				dialogZip.close();
-			}else{
-				document.getElementById(DIALOG_BACKDROP_FALLBACK_ID).style.display='none';
+			} else {
+				document.getElementById(DIALOG_BACKDROP_FALLBACK_ID).style.display = 'none';
 			}
 			_unzipEntry(this.zipEntry, onUnzip);
 		}
 
-		if (onUnzip === RomPatcherWeb.provideRomFile) {
+		if (onUnzip === romPatcherWeb.provideRomFile) {
 			dialogZipMessage.innerHTML = _('ROM file:');
-		} else if (onUnzip === RomPatcherWeb.providePatchFile) {
+		} else if (onUnzip === romPatcherWeb.providePatchFile) {
 			dialogZipMessage.innerHTML = _('Patch file:');
-		}else{
+		} else {
 			throw new Error('ZIPManager._unzipEntry: invalid onUnzip callback');
 		}
 
@@ -990,14 +1095,14 @@ const ZIPManager = (function (romPatcherWeb) {
 		}
 
 
-		if(typeof dialogZip.showModal === 'function'){
+		if (typeof dialogZip.showModal === 'function') {
 			if (!document.getElementById(dialogZip.id))
 				document.body.appendChild(dialogZip);
 
 			dialogZip.showModal();
-		}else{
+		} else {
 			/* fallback for incompatible browsers */
-			if (!document.getElementById(DIALOG_BACKDROP_FALLBACK_ID)){
+			if (!document.getElementById(DIALOG_BACKDROP_FALLBACK_ID)) {
 				const dialogBackdrop = document.createElement('div');
 				dialogBackdrop.id = DIALOG_BACKDROP_FALLBACK_ID;
 				dialogBackdrop.className = 'rom-patcher-dialog-backdrop';
@@ -1014,16 +1119,16 @@ const ZIPManager = (function (romPatcherWeb) {
 				document.body.appendChild(dialogBackdrop);
 			}
 
-			document.getElementById(DIALOG_BACKDROP_FALLBACK_ID).style.display='flex';
-			dialogZip.style.display='block';
+			document.getElementById(DIALOG_BACKDROP_FALLBACK_ID).style.display = 'flex';
+			dialogZip.style.display = 'block';
 		}
 	}
 
 	const _unzipError = function (zipReader) {
 		if (zipReader.message)
 			console.error('zip.js: ' + zipReader.message);
-		RomPatcherWeb.enable();
-		RomPatcherWeb.setErrorMessage(_('Error unzipping file'), 'error');
+		romPatcherWeb.enable();
+		romPatcherWeb.setErrorMessage(_('Error unzipping file'), 'error');
 	};
 
 
@@ -1042,13 +1147,13 @@ const ZIPManager = (function (romPatcherWeb) {
 						const filteredEntries = _filterEntriesRoms(zipEntries);
 
 						if (filteredEntries.length === 1) {
-							_unzipEntry(filteredEntries[0], RomPatcherWeb.provideRomFile);
+							_unzipEntry(filteredEntries[0], romPatcherWeb.provideRomFile);
 						} else if (filteredEntries.length > 1) {
-							_showFilePicker(filteredEntries, RomPatcherWeb.provideRomFile);
-							RomPatcherWeb.enable();
+							_showFilePicker(filteredEntries, romPatcherWeb.provideRomFile);
+							romPatcherWeb.enable();
 						} else {
 							/* no possible patchable files found in zip, treat zip file as ROM file */
-							RomPatcherWeb.calculateCurrentRomChecksums();
+							romPatcherWeb.calculateCurrentRomChecksums();
 						}
 					});
 				},
@@ -1066,11 +1171,11 @@ const ZIPManager = (function (romPatcherWeb) {
 						const filteredEntries = _filterEntriesPatches(zipEntries);
 
 						if (filteredEntries.length === 1) {
-							_unzipEntry(filteredEntries[0], RomPatcherWeb.providePatchFile);
+							_unzipEntry(filteredEntries[0], romPatcherWeb.providePatchFile);
 						} else if (filteredEntries.length > 1) {
-							_showFilePicker(filteredEntries, RomPatcherWeb.providePatchFile);
+							_showFilePicker(filteredEntries, romPatcherWeb.providePatchFile);
 						} else {
-							RomPatcherWeb.providePatchFile(null);
+							romPatcherWeb.providePatchFile(null);
 						}
 
 					});
@@ -1091,16 +1196,16 @@ const ZIPManager = (function (romPatcherWeb) {
 
 						if (filteredEntriesRoms.length && filteredEntriesPatches.length === 0) {
 							if (filteredEntriesRoms.length === 1) {
-								_unzipEntry(filteredEntriesRoms[0], RomPatcherWeb.provideRomFile);
+								_unzipEntry(filteredEntriesRoms[0], romPatcherWeb.provideRomFile);
 							} else {
-								_showFilePicker(filteredEntriesRoms, RomPatcherWeb.provideRomFile);
-								RomPatcherWeb.enable();
+								_showFilePicker(filteredEntriesRoms, romPatcherWeb.provideRomFile);
+								romPatcherWeb.enable();
 							}
 						} else if (filteredEntriesPatches.length && filteredEntriesRoms.length === 0) {
 							if (filteredEntriesPatches.length === 1) {
-								_unzipEntry(filteredEntriesPatches[0], RomPatcherWeb.providePatchFile);
+								_unzipEntry(filteredEntriesPatches[0], romPatcherWeb.providePatchFile);
 							} else {
-								_showFilePicker(filteredEntriesPatches, RomPatcherWeb.providePatchFile);
+								_showFilePicker(filteredEntriesPatches, romPatcherWeb.providePatchFile);
 							}
 						} else {
 							console.warn('ZIPManager.unzipAny: zip file contains both ROMs and patches, cannot guess');
@@ -1149,7 +1254,7 @@ const ZIPManager = (function (romPatcherWeb) {
 
 									select.addEventListener('change', function (evt) {
 										const fileIndex = parseInt(this.value);
-										_unzipEntry(filteredEntries[fileIndex], RomPatcherWeb.providePatchFile);
+										_unzipEntry(filteredEntries[fileIndex], romPatcherWeb.providePatchFile);
 									});
 								} else {
 									throw new Error('rom-patcher-select-file-patch not found');
@@ -1157,10 +1262,10 @@ const ZIPManager = (function (romPatcherWeb) {
 							}
 
 							//_setPatchInputSpinner(false);
-							_unzipEntry(filteredEntries[0], RomPatcherWeb.providePatchFile);
+							_unzipEntry(filteredEntries[0], romPatcherWeb.providePatchFile);
 						} else {
-							RomPatcherWeb.setErrorMessage(_('No valid patches found in ZIP'), 'error');
-							RomPatcherWeb.disable();
+							romPatcherWeb.setErrorMessage(_('No valid patches found in ZIP'), 'error');
+							romPatcherWeb.disable();
 						}
 					});
 				},
@@ -1250,7 +1355,7 @@ const PatchBuilderWeb = (function (romPatcherWeb) {
 	};
 
 	var initialized = false;
-	return{
+	return {
 		isInitialized: function () {
 			return initialized;
 		},
@@ -1258,17 +1363,21 @@ const PatchBuilderWeb = (function (romPatcherWeb) {
 		initialize: function () {
 			if (initialized)
 				throw new Error('Patch Builder JS was already initialized');
+			else if (!romPatcherWeb.isInitialized())
+				throw new Error('Rom Patcher JS must be initialized before Patch Builder JS');
 
 			document.getElementById('patch-builder-button-create').disabled = true;
-	
+
 			document.getElementById('patch-builder-input-file-original').addEventListener('change', function () {
 				_setElementsStatus(false);
 				this.classList.remove('empty');
 				originalRom = new BinFile(this.files[0], function (evt) {
 					_setElementsStatus(true);
-	
+
 					if (RomPatcher.isRomTooBig(originalRom))
 						_setToastError(_('Using big files is not recommended'), 'warning');
+					else if (ZIPManager.isZipFile(originalRom))
+						_setToastError(_('Patch creation is not compatible with zipped ROMs'), 'warning');
 				});
 			});
 			document.getElementById('patch-builder-input-file-modified').addEventListener('change', function () {
@@ -1276,9 +1385,11 @@ const PatchBuilderWeb = (function (romPatcherWeb) {
 				this.classList.remove('empty');
 				modifiedRom = new BinFile(this.files[0], function (evt) {
 					_setElementsStatus(true);
-	
+
 					if (RomPatcher.isRomTooBig(modifiedRom))
 						_setToastError(_('Using big files is not recommended'), 'warning');
+					else if (ZIPManager.isZipFile(modifiedRom))
+						_setToastError(_('Patch creation is not compatible with zipped ROMs'), 'warning');
 				});
 			});
 			document.getElementById('patch-builder-button-create').addEventListener('click', function () {
@@ -1298,6 +1409,7 @@ const PatchBuilderWeb = (function (romPatcherWeb) {
 
 			console.log('Patch Builder JS initialized');
 			initialized = true;
+			_setElementsStatus(true);
 		}
 	}
 }(RomPatcherWeb));
diff --git a/rom-patcher-js/modules/RomPatcher.format.vcdiff.js b/rom-patcher-js/modules/RomPatcher.format.vcdiff.js
index 3040d0d..ab0f3f9 100644
--- a/rom-patcher-js/modules/RomPatcher.format.vcdiff.js
+++ b/rom-patcher-js/modules/RomPatcher.format.vcdiff.js
@@ -184,14 +184,19 @@ VCDIFF.fromFile=function(file){
 
 function VCDIFF_Parser(binFile, offset)
 {
-    BinFile.call(this, 0);
 	this.fileSize=binFile.fileSize;
 	this._u8array=binFile._u8array;
-	this._dataView=binFile._dataView;
     this.offset=offset || 0;
-}
 
-VCDIFF_Parser.prototype=Object.create(BinFile.prototype);
+	/* reimplement readU8, readU32 and skip from BinFile */
+	/* in web implementation, there are no guarantees BinFile will be dynamically loaded before this one */
+	/* so we cannot rely on cloning BinFile.prototype */
+	this.readU8 = binFile.readU8;
+	this.readU32 = binFile.readU32;
+	this.skip = binFile.skip;
+	this.isEOF = binFile.isEOF;
+	this.seek = binFile.seek;
+}
 VCDIFF_Parser.prototype.read7BitEncodedInt=function(){
 	var num=0, bits = 0;
 
diff --git a/test.js b/test.js
index c7e9821..695e0cb 100644
--- a/test.js
+++ b/test.js
@@ -14,24 +14,27 @@
 		- ROM:   Super Mario Land 2 - 6 Golden Coins (USA, Europe).gb [CRC32=d5ec24e4]
 	- BPS test
 		- Patch: https://www.romhacking.net/translations/6297/
-		- ROM:  Samurai Kid (Japan).gbc [CRC32=44a9ddfb]	
+		- ROM:   Samurai Kid (Japan).gbc [CRC32=44a9ddfb]	
 	- UPS test
 		- Patch: https://mother3.fobby.net/
-		- ROM:  Mother 3 (Japan).gba [CRC32=42ac9cb9]
+		- ROM:   Mother 3 (Japan).gba [CRC32=42ac9cb9]
 	- APS test
 		- Patch: http://dorando.emuverse.com/projects/eduardo_a2j/zelda-ocarina-of-time.html
-		- ROM:  Legend of Zelda, The - Ocarina of Time (USA).z64 [CRC32=7e107c35]
+		- ROM:   Legend of Zelda, The - Ocarina of Time (USA).z64 [CRC32=7e107c35]
 	- RUP test
 		- Patch: https://www.romhacking.net/translations/843/
-		- ROM:  Uchuu no Kishi - Tekkaman Blade (Japan).sfc [CRC32=cd16c529]
+		- ROM:   Uchuu no Kishi - Tekkaman Blade (Japan).sfc [CRC32=cd16c529]
+	- xdelta test
+		- Patch: https://www.romhacking.net/hacks/2871/
+		- ROM:   New Super Mario Bros. (USA, Australia).nds [CRC32=0197576a]
 */
 
 const chalk=require('chalk');
 const { existsSync }=require('fs');
 
-const BinFile = require('./app/modules/BinFile');
-const HashCalculator = require('./app/modules/HashCalculator');
-const RomPatcher = require('./app/RomPatcher');
+const BinFile = require('./rom-patcher-js/modules/BinFile');
+const HashCalculator = require('./rom-patcher-js/modules/HashCalculator');
+const RomPatcher = require('./rom-patcher-js/RomPatcher');
 
 
 
@@ -77,10 +80,17 @@ const TEST_PATCHES=[
 		patchCrc32:0x621ab323,
 		patchDownload:'https://www.romhacking.net/hacks/4633/',
 		outputCrc32:0xe83e9b0a
+	},{
+		title:'NSMB Hack Domain Infusion',
+		romFile:'New Super Mario Bros. (USA, Australia).nds',
+		romCrc32:0x0197576a,
+		patchFile:'nsmb_infusion10a.xdelta',
+		patchCrc32:0xa211f97c,
+		patchDownload:'https://www.romhacking.net/hacks/2871/',
+		outputCrc32:0x9cecd976
 	}
 ];
 
-
 const _test=function(title, testFunction){
 	try{
 		const startTime=(new Date()).getTime();
diff --git a/webapp/style.css b/webapp/style.css
index 5fe2d62..e7def58 100644
--- a/webapp/style.css
+++ b/webapp/style.css
@@ -208,7 +208,10 @@ select:focus:not(:disabled),
 input[type=checkbox].styled:focus:not(:disabled){
 	box-shadow: var(--rom-patcher-color-primary-focus) 0 0 0 2px;
 }
-input[type=file].w100, select.w100{width:100%}
+#rom-patcher-container input[type=file],
+#rom-patcher-container select,
+#patch-builder-container input[type=file]
+{width:100%}
 input[type=file]{padding:6px 10px}
 input[type=file]::file-selector-button{display:none}
 select{
diff --git a/webapp/webapp.js b/webapp/webapp.js
index 5624e2b..adce8d3 100644
--- a/webapp/webapp.js
+++ b/webapp/webapp.js
@@ -101,6 +101,9 @@ window.addEventListener('load', function (evt) {
 	});
 
 	document.getElementById('switch-create-button').addEventListener('click', function () {
+		if(!RomPatcherWeb.isInitialized())
+			throw new Error('Rom Patcher JS is not initialized yet');
+
 		if (/disabled/.test(document.getElementById('switch-create').className)) {
 			try{
 				if(!PatchBuilderWeb.isInitialized())