diff --git a/package.json b/package.json
index 62df424..0194551 100644
--- a/package.json
+++ b/package.json
@@ -26,6 +26,7 @@
     "express": "^4.16.2",
     "glob": "^7.1.2",
     "locate-character": "^2.0.5",
+    "mime": "^2.2.0",
     "mkdirp": "^0.5.1",
     "mri": "^1.1.0",
     "node-fetch": "^1.7.3",
@@ -36,8 +37,7 @@
     "serialize-javascript": "^1.4.0",
     "url-parse": "^1.2.0",
     "walk-sync": "^0.3.2",
-    "webpack": "^3.10.0",
-    "webpack-hot-middleware": "^2.21.0"
+    "webpack": "^3.10.0"
   },
   "devDependencies": {
     "@std/esm": "^0.19.7",
@@ -63,9 +63,7 @@
     "svelte-loader": "^2.3.2",
     "ts-node": "^4.1.0",
     "tslib": "^1.8.1",
-    "typescript": "^2.6.2",
-    "wait-on": "^2.0.2",
-    "wait-port": "^0.2.2"
+    "typescript": "^2.6.2"
   },
   "scripts": {
     "cy:open": "cypress open",
diff --git a/src/cli/dev.ts b/src/cli/dev.ts
index 5615186..a7e02f3 100644
--- a/src/cli/dev.ts
+++ b/src/cli/dev.ts
@@ -1,12 +1,17 @@
 import * as fs from 'fs';
 import * as path from 'path';
+import * as net from 'net';
 import * as chalk from 'chalk';
 import * as child_process from 'child_process';
+import * as http from 'http';
+import mkdirp from 'mkdirp';
+import rimraf from 'rimraf';
+import { wait_for_port } from './utils';
 import { create_compilers, create_app, create_routes, create_serviceworker, create_template } from 'sapper/core.js';
 
 type Deferred = {
 	promise?: Promise<any>;
-	fulfil?: (value: any) => void;
+	fulfil?: (value?: any) => void;
 	reject?: (err: Error) => void;
 }
 
@@ -21,61 +26,61 @@ function deferred() {
 	return d;
 }
 
+function create_hot_update_server(port: number, interval = 10000) {
+	const clients = new Set();
+
+	const server = http.createServer((req, res) => {
+		if (req.url !== '/hmr') return;
+
+		req.socket.setKeepAlive(true);
+		res.writeHead(200, {
+			'Access-Control-Allow-Origin': '*',
+			'Content-Type': 'text/event-stream;charset=utf-8',
+			'Cache-Control': 'no-cache, no-transform',
+			'Connection': 'keep-alive',
+			// While behind nginx, event stream should not be buffered:
+			// http://nginx.org/docs/http/ngx_http_proxy_module.html#proxy_buffering
+			'X-Accel-Buffering': 'no'
+		});
+
+		res.write('\n');
+
+		clients.add(res);
+		req.on('close', () => {
+			clients.delete(res);
+		});
+	});
+
+	server.listen(port);
+
+	function send(data: any) {
+		clients.forEach(client => {
+			client.write(`data: ${JSON.stringify(data)}\n\n`);
+		});
+	}
+
+	setInterval(() => {
+		send(null)
+	}, interval);
+
+	return { send };
+}
+
 export default function create_watcher(src: string, dir: string) {
+	rimraf.sync(dir);
+	mkdirp.sync(dir);
+
+	const chokidar = require('chokidar');
+
 	// initial build
 	const routes = create_routes({ src });
 	create_app({ routes, src, dev: true });
 
+	const hot_update_server = create_hot_update_server(23456); // TODO robustify port selection
+
+	// TODO watch the configs themselves?
 	const compilers = create_compilers();
 
-	const deferreds = {
-		client: deferred(),
-		server: deferred()
-	};
-
-	const invalidate = () => Promise.all([
-		deferreds.client.promise,
-		deferreds.server.promise
-	]).then(([client_stats, server_stats]) => {
-		const client_info = client_stats.toJson();
-		fs.writeFileSync(path.join(dir, 'stats.client.json'), JSON.stringify(client_info, null, '  '));
-
-		const server_info = server_stats.toJson();
-		fs.writeFileSync(path.join(dir, 'stats.server.json'), JSON.stringify(server_info, null, '  '));
-
-		const client_files = client_info.assets.map((chunk: { name: string }) => `/client/${chunk.name}`);
-
-		return create_serviceworker({
-			routes: create_routes({ src }),
-			client_files,
-			src
-		});
-	});
-
-	function watch_compiler(type: 'client' | 'server', callback: (err: Error) => void) {
-		const compiler = compilers[type];
-
-		compiler.plugin('invalid', (filename: string) => {
-			console.log(chalk.cyan(`${type} bundle invalidated, file changed: ${chalk.bold(filename)}`));
-			deferreds[type] = deferred();
-			watcher.ready = invalidate();
-		});
-
-		compiler.plugin('failed', (err: Error) => {
-			deferreds[type].reject(err);
-		});
-
-		return compiler.watch({}, (err: Error, stats: any) => {
-			if (stats.hasErrors()) {
-				deferreds[type].reject(stats.toJson().errors[0]);
-			} else {
-				deferreds[type].fulfil(stats);
-			}
-		});
-	}
-
-	const chokidar = require('chokidar');
-
 	function watch_files(pattern: string, callback: () => void) {
 		const watcher = chokidar.watch(pattern, {
 			persistent: false
@@ -96,11 +101,114 @@ export default function create_watcher(src: string, dir: string) {
 		// TODO reload current page?
 	});
 
-	watch_compiler('client', () => {
+	let proc: child_process.ChildProcess;
 
+	const deferreds = {
+		server: deferred(),
+		client: deferred()
+	};
+
+	const times = {
+		client_start: Date.now(),
+		server_start: Date.now(),
+		serviceworker_start: Date.now()
+	};
+
+	compilers.server.plugin('invalid', () => {
+		times.server_start = Date.now();
+		// TODO print message
+		deferreds.server = deferred();
 	});
 
-	watch_compiler('server', () => {
+	compilers.server.watch({}, (err: Error, stats: any) => {
+		if (err) {
+			console.error(chalk.red(err.message));
+		} else if (stats.hasErrors()) {
+			// print errors. TODO notify client
+			stats.toJson().errors.forEach((error: Error) => {
+				console.error(error); // TODO make this look nice
+			});
+		} else {
+			console.log(`built server in ${Date.now() - times.server_start}ms`); // TODO prettify
 
+			const server_info = stats.toJson();
+			fs.writeFileSync(path.join(dir, 'server_info.json'), JSON.stringify(server_info, null, '  '));
+
+			deferreds.client.promise.then(() => {
+				if (proc) proc.kill();
+
+				proc = child_process.fork(`${dir}/server.js`, [], {
+					cwd: process.cwd(),
+					env: Object.assign({}, process.env)
+				});
+
+				wait_for_port(3000, deferreds.server.fulfil); // TODO control port
+			});
+		}
 	});
+
+	compilers.client.plugin('invalid', (filename: string) => {
+		times.client_start = Date.now();
+
+		deferreds.client = deferred();
+
+		// TODO print message
+		fs.readdirSync(path.join(dir, 'client')).forEach(file => {
+			fs.unlinkSync(path.join(dir, 'client', file));
+		});
+	});
+
+	compilers.client.watch({}, (err: Error, stats: any) => {
+		if (err) {
+			console.error(chalk.red(err.message));
+		} else if (stats.hasErrors()) {
+			// print errors. TODO notify client
+			stats.toJson().errors.forEach((error: Error) => {
+				console.error(error); // TODO make this look nice
+			});
+		} else {
+			console.log(`built client in ${Date.now() - times.client_start}ms`); // TODO prettify
+
+			const client_info = stats.toJson();
+			fs.writeFileSync(path.join(dir, 'client_info.json'), JSON.stringify(client_info, null, '  '));
+			deferreds.client.fulfil();
+
+			const client_files = client_info.assets.map((chunk: { name: string }) => `/client/${chunk.name}`);
+
+			deferreds.server.promise.then(() => {
+				hot_update_server.send({
+					status: 'completed'
+				});
+			});
+
+			return create_serviceworker({
+				routes: create_routes({ src }),
+				client_files,
+				src
+			});
+		}
+	});
+
+	if (compilers.serviceworker) {
+		compilers.serviceworker.plugin('invalid', (filename: string) => {
+			times.serviceworker_start = Date.now();
+		});
+
+		compilers.client.watch({}, (err: Error, stats: any) => {
+			if (err) {
+				// TODO notify client
+			} else if (stats.hasErrors()) {
+				// print errors. TODO notify client
+				stats.toJson().errors.forEach((error: Error) => {
+					console.error(error); // TODO make this look nice
+				});
+			} else {
+				console.log(`built service worker in ${Date.now() - times.serviceworker_start}ms`); // TODO prettify
+
+				const serviceworker_info = stats.toJson();
+				fs.writeFileSync(path.join(dir, 'serviceworker_info.json'), JSON.stringify(serviceworker_info, null, '  '));
+				// TODO trigger reload?
+			}
+		});
+	}
 }
\ No newline at end of file
diff --git a/src/cli/export.ts b/src/cli/export.ts
index 557e32b..50960bc 100644
--- a/src/cli/export.ts
+++ b/src/cli/export.ts
@@ -5,6 +5,7 @@ import express from 'express';
 import cheerio from 'cheerio';
 import URL from 'url-parse';
 import fetch from 'node-fetch';
+import { wait_for_port } from './utils';
 
 const { OUTPUT_DIR = 'dist' } = process.env;
 
@@ -55,8 +56,6 @@ export default async function exporter(dir: string) { // dir === '.sapper'
 		}
 	});
 
-	await require('wait-port')({ port });
-
 	function handle(url: URL) {
 		if (url.origin !== origin) return;
 
@@ -85,6 +84,8 @@ export default async function exporter(dir: string) { // dir === '.sapper'
 			});
 	}
 
-	return handle(new URL(origin)) // TODO all static routes
-		.then(() => proc.kill());
+	wait_for_port(port, () => {
+		handle(new URL(origin)) // TODO all static routes
+			.then(() => proc.kill())
+	});
 }
\ No newline at end of file
diff --git a/src/cli/utils.ts b/src/cli/utils.ts
new file mode 100644
index 0000000..6fd1a1e
--- /dev/null
+++ b/src/cli/utils.ts
@@ -0,0 +1,18 @@
+import * as net from 'net';
+
+export function wait_for_port(port: number, cb: () => void) {
+	const socket = net.createConnection({ port }, () => {
+		cb();
+		socket.destroy();
+	});
+
+	socket.on('error', err => {
+		setTimeout(() => {
+			wait_for_port(port, cb);
+		}, 100);
+	});
+
+	setTimeout(() => {
+		socket.destroy();
+	}, 100);
+}
\ No newline at end of file
diff --git a/src/core/create_app.ts b/src/core/create_app.ts
index c934653..4430f47 100644
--- a/src/core/create_app.ts
+++ b/src/core/create_app.ts
@@ -18,7 +18,8 @@ export default function create_app({ routes, src, dev }: {
 
 function generate_client(routes: Route[], src: string, dev: boolean) {
 	let code = `
-		// This file is generated by Sapper — do not edit it!\nexport const routes = [
+		// This file is generated by Sapper — do not edit it!
+		export const routes = [
 			${routes
 				.filter(route => route.type === 'page')
 				.map(route => {
@@ -34,10 +35,18 @@ function generate_client(routes: Route[], src: string, dev: boolean) {
 
 	if (dev) {
 		const hmr_client = posixify(
-			require.resolve(`webpack-hot-middleware/client`)
+			path.resolve(__dirname, 'src/hmr-client.js')
 		);
 
-		code += `\n\nimport('${hmr_client}?path=/__webpack_hmr&timeout=20000'); if (module.hot) module.hot.accept();`;
+		const PORT = 23456; // TODO robustify this — needs to be controlled by the dev task
+
+		code += `
+
+			if (module.hot) {
+				import('${hmr_client}').then(client => {
+					client.connect(${PORT});
+				});
+			}`.replace(/^\t{3}/gm, '');
 	}
 
 	return code;
diff --git a/src/core/create_serviceworker.ts b/src/core/create_serviceworker.ts
index d6841c8..1e07182 100644
--- a/src/core/create_serviceworker.ts
+++ b/src/core/create_serviceworker.ts
@@ -13,6 +13,7 @@ export default function create_serviceworker({ routes, client_files, src }: {
 	const assets = glob.sync('**', { cwd: 'assets', nodir: true });
 
 	let code = `
+		// This file is generated by Sapper — do not edit it!
 		export const timestamp = ${Date.now()};
 
 		export const assets = [\n\t${assets.map((x: string) => `"${x}"`).join(',\n\t')}\n];
@@ -20,7 +21,7 @@ export default function create_serviceworker({ routes, client_files, src }: {
 		export const shell = [\n\t${client_files.map((x: string) => `"${x}"`).join(',\n\t')}\n];
 
 		export const routes = [\n\t${routes.filter((r: Route) => r.type === 'page').map((r: Route) => `{ pattern: ${r.pattern} }`).join(',\n\t')}\n];
-	`.replace(/^\t\t/gm, '');
+	`.replace(/^\t\t/gm, '').trim();
 
 	write('app/manifest/service-worker.js', code);
 }
\ No newline at end of file
diff --git a/src/hmr-client.js b/src/hmr-client.js
new file mode 100644
index 0000000..88938dc
--- /dev/null
+++ b/src/hmr-client.js
@@ -0,0 +1,28 @@
+let source;
+
+function check() {
+	if (module.hot.status() === 'idle') {
+		module.hot.check(true).then(modules => {
+			console.log(`HMR updated`);
+		});
+	}
+}
+
+export function connect(port) {
+	if (source || !window.EventSource) return;
+
+	source = new EventSource(`http://localhost:${port}/hmr`);
+
+	source.onopen = function(event) {
+		console.log(`HMR connected`);
+	};
+
+	source.onmessage = function(event) {
+		const data = JSON.parse(event.data);
+		if (!data) return; // just a heartbeat
+
+		if (data.status === 'completed') {
+			check();
+		}
+	};
+}
\ No newline at end of file
diff --git a/src/middleware/TO_MOVE_create_watcher.ts b/src/middleware/TO_MOVE_create_watcher.ts
deleted file mode 100644
index 3c4f1b4..0000000
--- a/src/middleware/TO_MOVE_create_watcher.ts
+++ /dev/null
@@ -1,109 +0,0 @@
-import * as fs from 'fs';
-import * as path from 'path';
-import chalk from 'chalk';
-import { create_app, create_serviceworker, create_routes, create_template } from 'sapper/core.js';
-import { dest } from '../config.js';
-
-type Deferred = {
-	promise?: Promise<any>;
-	fulfil?: (value: any) => void;
-	reject?: (err: Error) => void;
-}
-
-function deferred() {
-	const d: Deferred = {};
-
-	d.promise = new Promise((fulfil, reject) => {
-		d.fulfil = fulfil;
-		d.reject = reject;
-	});
-
-	return d;
-}
-
-export default function create_watcher({ compilers, dev, entry, src, onroutes, ontemplate }) {
-	const deferreds = {
-		client: deferred(),
-		server: deferred()
-	};
-
-	const invalidate = () => Promise.all([
-		deferreds.client.promise,
-		deferreds.server.promise
-	]).then(([client_stats, server_stats]) => {
-		const client_info = client_stats.toJson();
-		fs.writeFileSync(path.join(dest, 'stats.client.json'), JSON.stringify(client_info, null, '  '));
-
-		const server_info = server_stats.toJson();
-		fs.writeFileSync(path.join(dest, 'stats.server.json'), JSON.stringify(server_info, null, '  '));
-
-		const client_files = client_info.assets.map((chunk: { name: string }) => `/client/${chunk.name}`);
-
-		return create_serviceworker({
-			routes: create_routes({ src }),
-			client_files,
-			src
-		});
-	});
-
-	function watch_compiler(type: 'client' | 'server') {
-		const compiler = compilers[type];
-
-		compiler.plugin('invalid', (filename: string) => {
-			console.log(chalk.cyan(`${type} bundle invalidated, file changed: ${chalk.bold(filename)}`));
-			deferreds[type] = deferred();
-			watcher.ready = invalidate();
-		});
-
-		compiler.plugin('failed', (err: Error) => {
-			deferreds[type].reject(err);
-		});
-
-		return compiler.watch({}, (err: Error, stats: any) => {
-			if (stats.hasErrors()) {
-				deferreds[type].reject(stats.toJson().errors[0]);
-			} else {
-				deferreds[type].fulfil(stats);
-			}
-		});
-	}
-
-	const chokidar = require('chokidar');
-
-	function watch_files(pattern: string, callback: () => void) {
-		const watcher = chokidar.watch(pattern, {
-			persistent: false
-		});
-
-		watcher.on('add', callback);
-		watcher.on('change', callback);
-		watcher.on('unlink', callback);
-	}
-
-	watch_files('routes/**/*.+(html|js|mjs)', () => {
-		const routes = create_routes({ src });
-		onroutes(routes);
-
-		create_app({ routes, src, dev });
-	});
-
-	watch_files('app/template.html', () => {
-		const template = create_template();
-		ontemplate(template);
-
-		// TODO reload current page?
-	});
-
-	const watcher = {
-		ready: invalidate(),
-		client: watch_compiler('client'),
-		server: watch_compiler('server'),
-
-		close: () => {
-			watcher.client.close();
-			watcher.server.close();
-		}
-	};
-
-	return watcher;
-}
\ No newline at end of file
diff --git a/src/middleware/index.ts b/src/middleware/index.ts
index 2838d45..56822af 100644
--- a/src/middleware/index.ts
+++ b/src/middleware/index.ts
@@ -1,5 +1,6 @@
 import * as fs from 'fs';
 import * as path from 'path';
+// import * as mime from 'mime';
 import mkdirp from 'mkdirp';
 import rimraf from 'rimraf';
 import serialize from 'serialize-javascript';
@@ -49,12 +50,26 @@ export default function middleware({ routes }: {
 			fn: () => assets.service_worker
 		}),
 
-		get_asset_handler({
-			filter: (pathname: string) => pathname.startsWith('/client/'),
-			type: 'application/javascript',
-			cache: 'max-age=31536000',
-			fn: (pathname: string) => assets.client[pathname.replace('/client/', '')]
-		}),
+		(req, res, next) => {
+			if (req.pathname.startsWith('/client/')) {
+				// const type = mime.getType(req.pathname);
+				const type = 'application/javascript'; // TODO might not be, if using e.g. CSS plugin
+
+				// TODO cache?
+				const rs = fs.createReadStream(path.join(dest, req.pathname.slice(1)));
+
+				rs.on('error', error => {
+					res.statusCode = 404;
+					res.end('not found');
+				});
+
+				res.setHeader('Content-Type', type);
+				res.setHeader('Cache-Control', 'max-age=31536000');
+				rs.pipe(res);
+			} else {
+				next();
+			}
+		},
 
 		get_route_handler(client_info.assetsByChunkName, () => assets, () => routes, () => template),