diff --git a/.flowconfig b/.flowconfig
index 91b9157..82f6f3e 100644
--- a/.flowconfig
+++ b/.flowconfig
@@ -25,3 +25,5 @@ misc/flowdeps.js
 [options]
 module.file_ext=.js
 module.file_ext=.njs
+module.ignore_non_literal_requires=true
+suppress_comment= \\(.\\|\n\\)*\\$FlowIgnore
diff --git a/adler32.flow.js b/adler32.flow.js
index 0aff418..fae0e23 100644
--- a/adler32.flow.js
+++ b/adler32.flow.js
@@ -23,7 +23,7 @@ var ADLER32;
 	}
 	/*jshint ignore:end */
 }(function(ADLER32) {
-ADLER32.version = '1.0.0';
+ADLER32.version = '1.1.0';
 /*::
 type ADLER32Type = number;
 type ABuf = Array<number> | Buffer;
diff --git a/adler32.js b/adler32.js
index 895d37f..7dfff51 100644
--- a/adler32.js
+++ b/adler32.js
@@ -21,7 +21,7 @@ var ADLER32;
 	}
 	/*jshint ignore:end */
 }(function(ADLER32) {
-ADLER32.version = '1.0.0';
+ADLER32.version = '1.1.0';
 function adler32_bstr(bstr, seed) {
 	var a = 1, b = 0, L = bstr.length, M = 0;
 	if(typeof seed === 'number') { a = seed & 0xFFFF; b = seed >>> 16; }
diff --git a/bin/adler32.njs b/bin/adler32.njs
index 534e09e..fa6b075 100755
--- a/bin/adler32.njs
+++ b/bin/adler32.njs
@@ -68,11 +68,18 @@ for(var i = 0; i < args.length; ++i) {
 if(!process.stdin.isTTY) filename = filename || "-";
 if(filename.length===0) die("adler32: must specify a filename ('-' for stdin)",1);
 
-function process_data(data/*:Buffer*/) {
-	var out/*:ADLER32Type*/ = X.buf(data, seed);
-	return console.log(fmt === "" ? out : require("printj").sprintf(fmt, out));
-}
+var adler32 = seed;
+// $FlowIgnore -- Writable is callable but type sig disagrees
+var writable = require('stream').Writable();
+writable._write = function(chunk, e, cb) { adler32 = X.buf(chunk, adler32); cb(); };
+writable._writev = function(chunks, cb) {
+	chunks.forEach(function(c) { adler32 = X.buf(c.chunk, adler32);});
+	cb();
+};
+writable.on('finish', function() {
+	console.log(fmt === "" ? adler32 : require("printj").sprintf(fmt, adler32));
+});
 
-if(filename === "-") process.stdin.pipe(require('concat-stream')(process_data));
-else if(fs.existsSync(filename)) process_data(fs.readFileSync(filename));
+if(filename === "-") process.stdin.pipe(writable);
+else if(fs.existsSync(filename)) fs.createReadStream(filename).pipe(writable);
 else die("adler32: " + filename + ": No such file or directory", 2);
diff --git a/bits/01_version.js b/bits/01_version.js
index b5778c1..3f19edd 100644
--- a/bits/01_version.js
+++ b/bits/01_version.js
@@ -1 +1 @@
-ADLER32.version = '1.0.0';
+ADLER32.version = '1.1.0';
diff --git a/ctest/adler32.js b/ctest/adler32.js
index 895d37f..7dfff51 100644
--- a/ctest/adler32.js
+++ b/ctest/adler32.js
@@ -21,7 +21,7 @@ var ADLER32;
 	}
 	/*jshint ignore:end */
 }(function(ADLER32) {
-ADLER32.version = '1.0.0';
+ADLER32.version = '1.1.0';
 function adler32_bstr(bstr, seed) {
 	var a = 1, b = 0, L = bstr.length, M = 0;
 	if(typeof seed === 'number') { a = seed & 0xFFFF; b = seed >>> 16; }
diff --git a/demo/browser.js b/demo/browser.js
index 2f46fb1..f7dcf00 100644
--- a/demo/browser.js
+++ b/demo/browser.js
@@ -2,7 +2,6 @@
 /*global ADLER32, console */
 var X = ADLER32;
 
-// $FlowIgnore
 function console_log() { if(typeof console !== 'undefined') console.log.apply(console, [].slice.call(arguments)); }
 
 function lpad(s, len, chr){
diff --git a/demo/work.js b/demo/work.js
new file mode 100644
index 0000000..7b87a28
--- /dev/null
+++ b/demo/work.js
@@ -0,0 +1,28 @@
+/* js-adler32 (C) 2014-present  SheetJS -- http://sheetjs.com */
+/*:: declare var ADLER32: ADLER32Module; */
+/*:: declare var self: DedicatedWorkerGlobalScope; */
+importScripts('../adler32.js');
+/*::self.*/postMessage({t:"ready"});
+
+var readler = function(f, adler, l) {
+	/*::self.*/postMessage({t:"iter", f:f, adler:adler, l:l, sz:f.size});
+	if(l >= f.size) return /*::self.*/postMessage({t:"done"});
+	var sz = 0x100000; if(l + sz > f.size) sz = f.size - l;
+	var d = f.slice(l, l + sz);
+	var r = new FileReader();
+	r.onload = function(e) {
+		var b = new Uint8Array(e.target.result);
+		var newadler = ADLER32.buf(b, adler);
+		/*::self.*/postMessage({t:"data", adler:newadler, bytes:l+sz});
+		readler(f, newadler, l + sz);
+	};
+	r.readAsArrayBuffer(d);
+};
+
+onmessage = function (oEvent) {
+	/*::self.*/postMessage({t:"start"});
+	var f/*:File*/ = oEvent.data;
+  var seed = 1;
+	readler(f, seed, 0);
+};
+
diff --git a/demo/worker.flow.js b/demo/worker.flow.js
new file mode 100644
index 0000000..8426bf4
--- /dev/null
+++ b/demo/worker.flow.js
@@ -0,0 +1,69 @@
+/*jshint browser:true */
+
+function lpad(s/*:string*/, len/*:number*/, chr/*:?string*/)/*:string*/{
+	var L/*:number*/ = len - s.length, C/*:string*/ = chr || " ";
+	if(L <= 0) return s;
+	return new Array(L+1).join(C) + s;
+}
+
+function is_defined(val/*:any*/, keys/*:Array<string>*/)/*:boolean*/ {
+	if(typeof val === "undefined") return false;
+	return keys.length === 0 || is_defined(val[keys[0]], keys.slice(1));
+}
+
+/*## Process Result */
+/*:: declare class HTMLPreElement extends HTMLElement { innerText?:string; } */
+function process_value(val/*:ADLER32Type*/, progress/*:number*/) {
+	var output = [];
+	output[0] = "Progress  : %" + lpad(progress.toFixed(2), 6, " ");
+	output[1] = "Signed    : " + val;
+	output[2] = "Unsigned  : " + (val>>>0);
+	output[3] = "Hex value : " + lpad((val>>>0).toString(16),8,'0');
+
+	var out/*:HTMLPreElement*/ = (document.getElementById('out')/*:any*/);
+	var o = output.join("\n");
+	if(typeof out.innerText == "undefined") out.textContent = o;
+	else out.innerText = o;
+}
+
+/*::
+type WMessage = {
+	t:string;
+	f:File;
+	adler:ADLER32Type;
+	l:number;
+	sz:number;
+	bytes:number;
+};
+*/
+
+/*# Drag and Drop File */
+var handle_drop/*:EventHandler*/ = (function(e/*:DragEvent*/) {
+	e.stopPropagation();
+	e.preventDefault();
+	if(!e.dataTransfer) return;
+	var files/*:FileList*/ = e.dataTransfer.files;
+	var f/*:File*/ = files[0];
+
+	var worker = new Worker("demo/work.js");
+	worker.postMessage(f);
+	worker.onmessage = function(M) { var m/*:WMessage*/ = (M.data/*:any*/); switch(m.t) {
+		case 'ready': break;
+		case 'start': break;
+		case 'data': process_value(m.adler, 100 * m.bytes / f.size); break;
+		case 'done': break;
+	} };
+}/*:any*/);
+
+var handle_drag/*:EventHandler*/ = (function (e/*:DragEvent*/) {
+	e.stopPropagation();
+	e.preventDefault();
+	if(e.dataTransfer) e.dataTransfer.dropEffect = 'copy';
+}/*:any*/);
+
+var drop/*:HTMLDivElement*/ = (document.getElementById('drop')/*:any*/);
+if(drop.addEventListener) {
+	drop.addEventListener('dragenter', handle_drag, false);
+	drop.addEventListener('dragover',  handle_drag, false);
+	drop.addEventListener('drop',      handle_drop, false);
+}
diff --git a/index.html b/index.html
index a719405..b5d43d2 100644
--- a/index.html
+++ b/index.html
@@ -1,5 +1,5 @@
 <!DOCTYPE html>
-<!-- adler32.js (C) 2014-present SheetJS http://sheetjs.com -->
+<!-- adler32.js (C) 2014-present  SheetJS http://sheetjs.com -->
 <!-- vim: set ts=2: -->
 <html>
 <head>
@@ -18,20 +18,27 @@
 #rawdata{
 	width:100%;
 }
+a { text-decoration: none }
 </style>
 </head>
 <body>
-<b>JS-ADLER32 Live Demo</b><br />
-<a href="https://git.io/adler32">Source Code Repo</a><br />
-<a href="https://git.io/adler32_issues">Issues?  Something look weird?  Click here and report an issue</a><br />
+<pre>
+<b><a href="http://sheetjs.com/bits">SheetJS JS-ADLER32 Live Demo</a></b>
+(text works back to IE6; drag and drop works back to IE10)
+(<b>This demo loads the entire file at once!</b>  For newer browsers, <a href="large.html">try the large file demo</a>)
 
+<a href="https://git.io/adler32">Source Code Repo</a>
+<a href="https://git.io/adler32_issues">Issues?  Something look weird?  Click here and report an issue</a>
+<br />
 <div id="drop">Drop a text file to compute the ADLER-32 checksum</div>
-<p><input type="file" name="xlfile" id="xlf" /> ... or click here to select a file</p>
-<textarea id="rawdata">... or paste text here ......</textarea>
+<input type="file" name="xlfile" id="xlf" /> ... or click here to select a file
+
+<textarea id="rawdata">... or paste text here</textarea>
 <input type="button" id="dotext" value="Click here to process the text"/><br />
-Advanced Demo Options: <br />
+<b>Advanced Demo Options:</b>
 Use readAsBinaryString: (when available) <input type="checkbox" name="userabs" checked><br />
-<pre id="out">.</pre>
+</pre>
+<pre id="out"></pre>
 <br />
 <script type="text/javascript">/* jshint browser: true */</script>
 <script src="shim.js"></script>
diff --git a/large.html b/large.html
new file mode 100644
index 0000000..3553ed6
--- /dev/null
+++ b/large.html
@@ -0,0 +1,52 @@
+<!DOCTYPE html>
+<!-- adler32.js (C) 2014-present  SheetJS http://sheetjs.com -->
+<!-- vim: set ts=2: -->
+<html>
+<head>
+<meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />
+<title>JS-ADLER32 Live Demo</title>
+<style>
+#drop{
+	border:2px dashed #bbb;
+	-moz-border-radius:5px;
+	-webkit-border-radius:5px;
+	border-radius:5px;
+	padding:25px;
+	text-align:center;
+	font:20pt bold,"Vollkorn";color:#bbb
+}
+#rawdata{
+	width:100%;
+}
+a { text-decoration: none }
+</style>
+</head>
+<body>
+<pre>
+<b><a href="http://sheetjs.com/bits">SheetJS JS-ADLER32 Live Demo</a></b>
+(text works back to IE6; drag and drop works back to IE10)
+
+<a href="https://git.io/adler32">Source Code Repo</a>
+<a href="https://git.io/adler32_issues">Issues?  Something look weird?  Click here and report an issue</a>
+<br />
+<div id="drop">Drop a text file to compute the ADLER-32 checksum</div>
+
+<pre id="out"></pre>
+<br />
+<script type="text/javascript">/* jshint browser: true */</script>
+<script src="shim.js"></script>
+<script src="adler32.js"></script>
+<script src="demo/worker.flow.js"></script>
+<script type="text/javascript">
+	var _gaq = _gaq || [];
+	_gaq.push(['_setAccount', 'UA-36810333-1']);
+	_gaq.push(['_trackPageview']);
+
+	(function() {
+		var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true;
+		ga.src = ('https:' == document.location.protocol ? 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js';
+		var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(ga, s);
+	})();
+</script>
+</body>
+</html>
diff --git a/package.json b/package.json
index 6c6a6ce..b1b0dcf 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
 	"name": "adler-32",
-	"version": "1.0.0",
+	"version": "1.1.0",
 	"author": "sheetjs",
 	"description": "Pure-JS ADLER-32",
 	"keywords": [ "adler32", "checksum" ],
@@ -9,13 +9,12 @@
 	},
 	"main": "./adler32",
 	"dependencies": {
-		"concat-stream":"",
-		"printj":"",
-		"exit-on-epipe":""
+		"printj":"~1.1.0",
+		"exit-on-epipe":"~1.0.1"
 	},
 	"devDependencies": {
-		"mocha":"",
-		"codepage":""
+		"mocha":"~2.5.3",
+		"codepage":"~1.10.0"
 	},
 	"repository": { "type":"git", "url":"git://github.com/SheetJS/js-adler32.git" },
 	"scripts": {