diff --git a/.gitignore b/.gitignore
index cb265cefb..93f136199 100755
--- a/.gitignore
+++ b/.gitignore
@@ -1,5 +1,2 @@
 node_modules
 npm-debug.log
-coverage.html
-lib-cov/
-dist
diff --git a/.travis.yml b/.travis.yml
index f935fb987..cbfebefd2 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -3,7 +3,7 @@ language: node_js
 node_js:
   - "4"
   - "6"
-  - "7"
+  - "8"
 git:
   depth: 1
 notifications:
diff --git a/Makefile b/Makefile
deleted file mode 100644
index da335f66d..000000000
--- a/Makefile
+++ /dev/null
@@ -1,16 +0,0 @@
-
-BENCHMARKS = $(shell find bench -type f ! -name 'runner.js')
-
-test:
-	@./node_modules/.bin/gulp test
-
-test-cov: lib-cov
-	EIO_COV=1 $(MAKE) test REPORTER=html-cov > coverage.html
-
-lib-cov:
-	jscoverage --no-highlight lib lib-cov
-
-bench:
-	@node $(PROFILEFLAGS) bench/runner.js $(BENCHMARKS)
-
-.PHONY: test test-cov bench
diff --git a/gulpfile.js b/gulpfile.js
deleted file mode 100644
index 1cd3a5d8e..000000000
--- a/gulpfile.js
+++ /dev/null
@@ -1,52 +0,0 @@
-const gulp = require('gulp');
-const mocha = require('gulp-mocha');
-const babel = require('gulp-babel');
-const nsp = require('gulp-nsp');
-const eslint = require('gulp-eslint');
-
-const TESTS = 'test/*.js';
-const REPORTER = 'dot';
-
-gulp.task('default', ['transpile']);
-
-gulp.task('test', ['nsp', 'lint'], function () {
-  if (parseInt(process.versions.node, 10) < 4 && process.env.EIO_WS_ENGINE !== 'ws') {
-    console.info('Node version < 4, skipping tests with uws engine');
-    process.exit();
-  }
-  return gulp.src(TESTS, {read: false})
-    .pipe(mocha({
-      slow: 500,
-      reporter: REPORTER,
-      bail: true
-    }))
-    .once('error', function (err) {
-      console.error(err.stack);
-      process.exit(1);
-    })
-    .once('end', function () {
-      process.exit();
-    });
-});
-
-gulp.task('lint', function () {
-  return gulp.src([
-    '*.js',
-    'lib/**/*.js',
-    'test/**/*.js'
-  ])
-    .pipe(eslint())
-    .pipe(eslint.format())
-    .pipe(eslint.failAfterError());
-});
-
-// By default, individual js files are transformed by babel and exported to /dist
-gulp.task('transpile', function () {
-  return gulp.src(['lib/**/*.js'], { base: 'lib' })
-        .pipe(babel({ 'presets': ['es2015'] }))
-        .pipe(gulp.dest('dist'));
-});
-
-gulp.task('nsp', function (cb) {
-  nsp({package: __dirname + '/package.json'}, cb);
-});
diff --git a/index.js b/index.js
deleted file mode 100644
index ebb4e1024..000000000
--- a/index.js
+++ /dev/null
@@ -1,4 +0,0 @@
-
-module.exports = process.env.EIO_COV
-  ? require('./lib-cov/engine.io')
-  : require('./lib/engine.io');
diff --git a/lib/server.js b/lib/server.js
index 09ab49ca0..57886b596 100644
--- a/lib/server.js
+++ b/lib/server.js
@@ -91,14 +91,6 @@ Server.errorMessages = {
 
 util.inherits(Server, EventEmitter);
 
-/**
- * Hash of open clients.
- *
- * @api public
- */
-
-Server.prototype.clients;
-
 /**
  * Initialize websocket server
  *
@@ -355,7 +347,7 @@ Server.prototype.handleUpgrade = function (req, socket, upgradeHead) {
       return;
     }
 
-    var head = new Buffer(upgradeHead.length);
+    var head = new Buffer(upgradeHead.length); // eslint-disable-line node/no-deprecated-api
     upgradeHead.copy(head);
     upgradeHead = null;
 
diff --git a/lib/socket.js b/lib/socket.js
index f77a4ca07..526707c26 100644
--- a/lib/socket.js
+++ b/lib/socket.js
@@ -91,7 +91,6 @@ Socket.prototype.onPacket = function (packet) {
     this.setPingTimeout();
 
     switch (packet.type) {
-
       case 'ping':
         debug('got ping');
         this.sendPacket('pong');
diff --git a/lib/transports/polling.js b/lib/transports/polling.js
index 6d5a20bef..6c5c0cc33 100644
--- a/lib/transports/polling.js
+++ b/lib/transports/polling.js
@@ -136,7 +136,7 @@ Polling.prototype.onDataRequest = function (req, res) {
   this.dataReq = req;
   this.dataRes = res;
 
-  var chunks = isBinary ? new Buffer(0) : '';
+  var chunks = isBinary ? new Buffer(0) : ''; // eslint-disable-line node/no-deprecated-api
   var self = this;
 
   function cleanup () {
@@ -162,7 +162,7 @@ Polling.prototype.onDataRequest = function (req, res) {
     }
 
     if (contentLength > self.maxHttpBufferSize) {
-      chunks = isBinary ? new Buffer(0) : '';
+      chunks = isBinary ? new Buffer(0) : ''; // eslint-disable-line node/no-deprecated-api
       req.connection.destroy();
     }
   }
diff --git a/package.json b/package.json
index 255deb076..35ba38b7f 100644
--- a/package.json
+++ b/package.json
@@ -2,7 +2,7 @@
   "name": "engine.io",
   "version": "3.1.0",
   "description": "The realtime engine behind Socket.IO. Provides the foundation of a bidirectional connection between client and server",
-  "main": "./lib/engine.io",
+  "main": "lib/engine.io",
   "author": "Guillermo Rauch <guillermo@learnboost.com>",
   "homepage": "https://github.com/socketio/engine.io",
   "contributors": [
@@ -33,17 +33,16 @@
     "cookie": "0.3.1"
   },
   "devDependencies": {
-    "babel-eslint": "5.0.0",
+    "babel-eslint": "^7.2.3",
     "babel-preset-es2015": "^6.24.0",
     "engine.io-client": "3.1.0",
-    "eslint-config-standard": "4.4.0",
-    "eslint-plugin-standard": "1.3.2",
+    "eslint": "^4.5.0",
+    "eslint-config-standard": "^10.2.1",
+    "eslint-plugin-import": "^2.7.0",
+    "eslint-plugin-node": "^5.1.1",
+    "eslint-plugin-promise": "^3.5.0",
+    "eslint-plugin-standard": "^3.0.1",
     "expect.js": "^0.3.1",
-    "gulp": "^3.9.1",
-    "gulp-babel": "^6.1.2",
-    "gulp-eslint": "1.1.1",
-    "gulp-mocha": "^4.3.0",
-    "gulp-nsp": "^2.4.1",
     "mocha": "^3.2.0",
     "s": "0.1.1",
     "superagent": "0.15.4"
@@ -52,14 +51,14 @@
     "uws": "~0.14.4"
   },
   "scripts": {
-    "test": "gulp test; EIO_WS_ENGINE=ws gulp test;"
+    "lint": "eslint lib/ test/ *.js",
+    "test": "npm run lint && mocha && EIO_WS_ENGINE=ws mocha"
   },
   "repository": {
     "type": "git",
     "url": "git@github.com:socketio/engine.io.git"
   },
   "files": [
-    "index.js",
     "lib/"
   ]
 }
diff --git a/test/jsonp.js b/test/jsonp.js
index b0ca0d973..99f18a674 100644
--- a/test/jsonp.js
+++ b/test/jsonp.js
@@ -11,7 +11,7 @@ var request = require('superagent');
 describe('JSONP', function () {
   before(function () {
     // we have to override the browser's functionality for JSONP
-    document = { // eslint-disable-line no-native-reassign, no-undef
+    document = { // eslint-disable-line no-global-assign
       body: {
         appendChild: function () {},
         removeChild: function () {}
@@ -44,10 +44,10 @@ describe('JSONP', function () {
           appendChild: function () {},
           submit: function () {
             request
-            .post(this.action)
-            .type('form')
-            .send({ d: self.areaValue })
-            .end(function () {});
+              .post(this.action)
+              .type('form')
+              .send({ d: self.areaValue })
+              .end(function () {});
           }
         };
         return form;
@@ -156,7 +156,7 @@ describe('JSONP', function () {
     });
 
     it('should arrive from server to client and back with binary data (pollingJSONP)', function (done) {
-      var binaryData = new Buffer(5);
+      var binaryData = Buffer.allocUnsafe(5);
       for (var i = 0; i < 5; i++) binaryData[i] = i;
       engine.on('connection', function (conn) {
         conn.on('message', function (msg) {
@@ -178,7 +178,7 @@ describe('JSONP', function () {
     it('should trigger when server closes a client', function (done) {
       var engine = listen({ allowUpgrades: false, transports: ['polling'] }, function (port) {
         var socket = new eioc.Socket('ws://localhost:' + port,
-            { transports: ['polling'], forceJSONP: true, upgrade: false });
+          { transports: ['polling'], forceJSONP: true, upgrade: false });
         var total = 2;
 
         engine.on('connection', function (conn) {
diff --git a/test/server.js b/test/server.js
index 8cdfc9db8..50164b81d 100644
--- a/test/server.js
+++ b/test/server.js
@@ -1,3 +1,4 @@
+/* eslint-disable standard/no-callback-literal */
 
 /**
  * Tests dependencies.
@@ -352,18 +353,18 @@ describe('server', function () {
         var socket = new eioc.Socket('ws://localhost:%d'.s(port));
         socket.on('open', function () {
           request.get('http://localhost:%d/engine.io/'.s(port))
-          .set({ connection: 'close' })
-          .query({ transport: 'websocket', sid: socket.id })
-          .end(function (err, res) {
-            expect(err).to.be(null);
-            expect(res.status).to.be(400);
-            expect(res.body.code).to.be(3);
-            socket.send('echo');
-            socket.on('message', function (msg) {
-              expect(msg).to.be('echo');
-              done();
+            .set({ connection: 'close' })
+            .query({ transport: 'websocket', sid: socket.id })
+            .end(function (err, res) {
+              expect(err).to.be(null);
+              expect(res.status).to.be(400);
+              expect(res.body.code).to.be(3);
+              socket.send('echo');
+              socket.on('message', function (msg) {
+                expect(msg).to.be('echo');
+                done();
+              });
             });
-          });
         });
       });
     });
@@ -1353,7 +1354,7 @@ describe('server', function () {
     });
 
     it('should arrive when binary data is sent as Buffer (ws)', function (done) {
-      var binaryData = new Buffer(5);
+      var binaryData = Buffer.allocUnsafe(5);
       for (var i = 0; i < binaryData.length; i++) {
         binaryData.writeInt8(i, i);
       }
@@ -1379,7 +1380,7 @@ describe('server', function () {
     });
 
     it('should arrive when binary data sent as Buffer (polling)', function (done) {
-      var binaryData = new Buffer(5);
+      var binaryData = Buffer.allocUnsafe(5);
       for (var i = 0; i < binaryData.length; i++) {
         binaryData.writeInt8(i, i);
       }
@@ -1406,7 +1407,7 @@ describe('server', function () {
     });
 
     it('should arrive as ArrayBuffer if requested when binary data sent as Buffer (ws)', function (done) {
-      var binaryData = new Buffer(5);
+      var binaryData = Buffer.allocUnsafe(5);
       for (var i = 0; i < binaryData.length; i++) {
         binaryData.writeInt8(i, i);
       }
@@ -1435,7 +1436,7 @@ describe('server', function () {
     });
 
     it('should arrive as ArrayBuffer if requested when binary data sent as Buffer (polling)', function (done) {
-      var binaryData = new Buffer(5);
+      var binaryData = Buffer.allocUnsafe(5);
       for (var i = 0; i < binaryData.length; i++) {
         binaryData.writeInt8(i, i);
       }
@@ -1516,8 +1517,8 @@ describe('server', function () {
         var socket = new eioc.Socket('ws://localhost:%d'.s(port), { transports: ['websocket'] });
         socket.on('open', function () {
           for (var i = 0; i < messageCount; i++) {
-//            connection.send('message: ' + i);   // works
-            connection.send(messagePayload + '|message: ' + i);   // does not work
+            //            connection.send('message: ' + i);   // works
+            connection.send(messagePayload + '|message: ' + i); // does not work
           }
           var receivedCount = 0;
           socket.on('message', function (msg) {
@@ -1614,7 +1615,8 @@ describe('server', function () {
         key: fs.readFileSync('test/fixtures/server.key'),
         cert: fs.readFileSync('test/fixtures/server.crt'),
         ca: fs.readFileSync('test/fixtures/ca.crt'),
-        requestCert: true
+        requestCert: true,
+        rejectUnauthorized: false
       };
 
       var opts = {
@@ -2309,7 +2311,7 @@ describe('server', function () {
     it('should compress by default', function (done) {
       var engine = listen({ transports: ['polling'] }, function (port) {
         engine.on('connection', function (conn) {
-          var buf = new Buffer(1024);
+          var buf = Buffer.allocUnsafe(1024);
           for (var i = 0; i < buf.length; i++) buf[i] = i % 0xff;
           conn.send(buf);
         });
@@ -2337,7 +2339,7 @@ describe('server', function () {
     it('should compress using deflate', function (done) {
       var engine = listen({ transports: ['polling'] }, function (port) {
         engine.on('connection', function (conn) {
-          var buf = new Buffer(1024);
+          var buf = Buffer.allocUnsafe(1024);
           for (var i = 0; i < buf.length; i++) buf[i] = i % 0xff;
           conn.send(buf);
         });
@@ -2365,7 +2367,7 @@ describe('server', function () {
     it('should set threshold', function (done) {
       var engine = listen({ transports: ['polling'], httpCompression: { threshold: 0 } }, function (port) {
         engine.on('connection', function (conn) {
-          var buf = new Buffer(10);
+          var buf = Buffer.allocUnsafe(10);
           for (var i = 0; i < buf.length; i++) buf[i] = i % 0xff;
           conn.send(buf);
         });
@@ -2390,7 +2392,7 @@ describe('server', function () {
     it('should disable compression', function (done) {
       var engine = listen({ transports: ['polling'], httpCompression: false }, function (port) {
         engine.on('connection', function (conn) {
-          var buf = new Buffer(1024);
+          var buf = Buffer.allocUnsafe(1024);
           for (var i = 0; i < buf.length; i++) buf[i] = i % 0xff;
           conn.send(buf);
         });
@@ -2415,7 +2417,7 @@ describe('server', function () {
     it('should disable compression per message', function (done) {
       var engine = listen({ transports: ['polling'] }, function (port) {
         engine.on('connection', function (conn) {
-          var buf = new Buffer(1024);
+          var buf = Buffer.allocUnsafe(1024);
           for (var i = 0; i < buf.length; i++) buf[i] = i % 0xff;
           conn.send(buf, { compress: false });
         });
@@ -2440,7 +2442,7 @@ describe('server', function () {
     it('should not compress when the byte size is below threshold', function (done) {
       var engine = listen({ transports: ['polling'] }, function (port) {
         engine.on('connection', function (conn) {
-          var buf = new Buffer(100);
+          var buf = Buffer.allocUnsafe(100);
           for (var i = 0; i < buf.length; i++) buf[i] = i % 0xff;
           conn.send(buf);
         });
@@ -2478,7 +2480,7 @@ describe('server', function () {
             done();
           };
 
-          var buf = new Buffer(100);
+          var buf = Buffer.allocUnsafe(100);
           for (var i = 0; i < buf.length; i++) buf[i] = i % 0xff;
           conn.send(buf, { compress: true });
         });
@@ -2500,7 +2502,7 @@ describe('server', function () {
             done();
           };
 
-          var buf = new Buffer(100);
+          var buf = Buffer.allocUnsafe(100);
           for (var i = 0; i < buf.length; i++) buf[i] = i % 0xff;
           conn.send(buf, { compress: true });
         });