diff --git a/.gitignore b/.gitignore
index 8f5b2905f2..da344e99ac 100644
--- a/.gitignore
+++ b/.gitignore
@@ -17,7 +17,7 @@
 
 # Ignore object files.
 *.o
-build/*.js
+build/
 tags
 bin/rippled
 Debug/*.*
diff --git a/.npmignore b/.npmignore
index 928256a82b..7378066b39 100644
--- a/.npmignore
+++ b/.npmignore
@@ -1,2 +1,4 @@
 lib-cov
 coverage.html
+src
+dist/bower
diff --git a/.travis.yml b/.travis.yml
index 5b666aaa3d..9fac3c25b5 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -1,9 +1,9 @@
 language: node_js
 node_js:
-  - "0.10"
+  - "0.12"
 before_script:
   - npm install -g eslint
-  - curl 'https://raw.githubusercontent.com/ripple/javascript-style-guide/master/eslintrc' > ./eslintrc
+  - curl 'https://raw.githubusercontent.com/ripple/javascript-style-guide/es6/eslintrc' > ./eslintrc
   - eslint --reset -c ./eslintrc $(git --no-pager diff --name-only -M100% --diff-filter=AM --relative $(git merge-base FETCH_HEAD origin/HEAD) FETCH_HEAD | grep "\.js$")
 script: MOCHA_REPORTER=tap npm test --coverage
 after_success:
diff --git a/Gulpfile.js b/Gulpfile.js
index 0a6944224b..bb3b5a7ed3 100644
--- a/Gulpfile.js
+++ b/Gulpfile.js
@@ -1,4 +1,7 @@
+/* eslint-disable no-var, no-param-reassign */
+/* these eslint rules are disabled because gulp does not support babel yet */
 'use strict';
+var _ = require('lodash');
 var gulp = require('gulp');
 var gutil = require('gulp-util');
 var watch = require('gulp-watch');
@@ -15,20 +18,33 @@ var argv = require('yargs').argv;
 
 var pkg = require('./package.json');
 
-function logPluginError(error) {
-  gutil.log(error.toString());
-}
-
-gulp.task('build', function(callback) {
-  webpack({
+function webpackConfig(extension, overrides) {
+  overrides = overrides || {};
+  var defaults = {
     cache: true,
     entry: './src/index.js',
     output: {
       library: 'ripple',
       path: './build/',
-      filename: ['ripple-', '.js'].join(pkg.version)
+      filename: ['ripple-', extension].join(pkg.version)
+    },
+    module: {
+      loaders: [{
+        test: /\.js$/,
+        exclude: /node_modules/,
+        loader: 'babel-loader?optional=runtime'
+      }]
     }
-  }, callback);
+  };
+  return _.assign({}, defaults, overrides);
+}
+
+function logPluginError(error) {
+  gutil.log(error.toString());
+}
+
+gulp.task('build', function(callback) {
+  webpack(webpackConfig('.js'), callback);
 });
 
 gulp.task('build-min', ['build'], function() {
@@ -39,17 +55,8 @@ gulp.task('build-min', ['build'], function() {
 });
 
 gulp.task('build-debug', function(callback) {
-  webpack({
-    cache: true,
-    entry: './src/index.js',
-    output: {
-      library: 'ripple',
-      path: './build/',
-      filename: ['ripple-', '-debug.js'].join(pkg.version)
-    },
-    debug: true,
-    devtool: 'eval'
-  }, callback);
+  var configOverrides = {debug: true, devtool: 'eval'};
+  webpack(webpackConfig('-debug.js', configOverrides), callback);
 });
 
 /**
@@ -64,51 +71,44 @@ function buildUseError(cons) {
 }
 
 gulp.task('build-core', function(callback) {
-  webpack({
-    entry: [
-      './src/remote.js'
-    ],
-    externals: [
-      {
-        './transaction': buildUseError('Transaction'),
-        './orderbook': buildUseError('OrderBook'),
-        './account': buildUseError('Account'),
-        './serializedobject': buildUseError('SerializedObject')
-      }
-    ],
-    output: {
-      library: 'ripple',
-      path: './build/',
-      filename: ['ripple-', '-core.js'].join(pkg.version)
-    },
+  var configOverrides = {
+    cache: false,
+    entry: './src/remote.js',
+    externals: [{
+      './transaction': buildUseError('Transaction'),
+      './orderbook': buildUseError('OrderBook'),
+      './account': buildUseError('Account'),
+      './serializedobject': buildUseError('SerializedObject')
+    }],
     plugins: [
       new webpack.optimize.UglifyJsPlugin()
     ]
-  }, callback);
+  };
+  webpack(webpackConfig('-core.js', configOverrides), callback);
 });
 
 gulp.task('bower-build', ['build'], function() {
   return gulp.src(['./build/ripple-', '.js'].join(pkg.version))
   .pipe(rename('ripple.js'))
-  .pipe(gulp.dest('./dist/'));
+  .pipe(gulp.dest('./dist/bower'));
 });
 
 gulp.task('bower-build-min', ['build-min'], function() {
   return gulp.src(['./build/ripple-', '-min.js'].join(pkg.version))
   .pipe(rename('ripple-min.js'))
-  .pipe(gulp.dest('./dist/'));
+  .pipe(gulp.dest('./dist/bower'));
 });
 
 gulp.task('bower-build-debug', ['build-debug'], function() {
   return gulp.src(['./build/ripple-', '-debug.js'].join(pkg.version))
   .pipe(rename('ripple-debug.js'))
-  .pipe(gulp.dest('./dist/'));
+  .pipe(gulp.dest('./dist/bower'));
 });
 
 gulp.task('bower-version', function() {
-  gulp.src('./dist/bower.json')
+  gulp.src('./dist/bower/bower.json')
   .pipe(bump({version: pkg.version}))
-  .pipe(gulp.dest('./dist/'));
+  .pipe(gulp.dest('./dist/bower'));
 });
 
 gulp.task('bower', ['bower-build', 'bower-build-min', 'bower-build-debug',
diff --git a/npm-shrinkwrap.json b/npm-shrinkwrap.json
index ae98582d71..4278d4f703 100644
--- a/npm-shrinkwrap.json
+++ b/npm-shrinkwrap.json
@@ -2,12 +2,22 @@
   "name": "ripple-lib",
   "version": "0.12.5-rc2",
   "npm-shrinkwrap-version": "5.4.0",
-  "node-version": "v0.10.38",
+  "node-version": "v0.12.3",
   "dependencies": {
     "async": {
       "version": "0.9.0",
       "resolved": "https://registry.npmjs.org/async/-/async-0.9.0.tgz"
     },
+    "babel-runtime": {
+      "version": "5.3.3",
+      "resolved": "https://registry.npmjs.org/babel-runtime/-/babel-runtime-5.3.3.tgz",
+      "dependencies": {
+        "core-js": {
+          "version": "0.9.9",
+          "resolved": "https://registry.npmjs.org/core-js/-/core-js-0.9.9.tgz"
+        }
+      }
+    },
     "bignumber.js": {
       "version": "2.0.7",
       "resolved": "https://registry.npmjs.org/bignumber.js/-/bignumber.js-2.0.7.tgz"
@@ -17,8 +27,8 @@
       "resolved": "https://registry.npmjs.org/extend/-/extend-1.2.1.tgz"
     },
     "lodash": {
-      "version": "3.7.0",
-      "resolved": "https://registry.npmjs.org/lodash/-/lodash-3.7.0.tgz"
+      "version": "3.8.0",
+      "resolved": "https://registry.npmjs.org/lodash/-/lodash-3.8.0.tgz"
     },
     "lru-cache": {
       "version": "2.5.2",
diff --git a/package.json b/package.json
index 8c18cb4b3a..26ca0c6441 100644
--- a/package.json
+++ b/package.json
@@ -3,19 +3,19 @@
   "version": "0.12.5-rc2",
   "description": "A JavaScript API for interacting with Ripple in Node.js and the browser",
   "files": [
-    "src/js/*",
+    "dist/npm/*",
     "bin/*",
     "build/*",
     "test/*",
-    "Makefile",
     "Gulpfile.js"
   ],
-  "main": "src/",
+  "main": "dist/npm/",
   "directories": {
     "test": "test"
   },
   "dependencies": {
     "async": "~0.9.0",
+    "babel-runtime": "^5.3.2",
     "bignumber.js": "^2.0.3",
     "extend": "~1.2.1",
     "lodash": "^3.1.0",
@@ -26,6 +26,9 @@
   },
   "devDependencies": {
     "assert-diff": "^1.0.1",
+    "babel": "^5.3.3",
+    "babel-core": "^5.3.2",
+    "babel-loader": "^5.0.0",
     "coveralls": "~2.10.0",
     "eslint": "^0.18.0",
     "gulp": "~3.8.10",
@@ -48,10 +51,12 @@
   },
   "scripts": {
     "build": "gulp",
+    "compile": "babel --optional runtime -d dist/npm/ src/",
+    "prepublish": "npm run compile",
     "postinstall": "cd node_modules/sjcl; ./configure --with-all --compress=none; make",
     "test": "istanbul test _mocha",
     "coveralls": "cat ./coverage/lcov.info | coveralls",
-    "lint": "if ! [ -f eslintrc ]; then curl -o eslintrc 'https://raw.githubusercontent.com/ripple/javascript-style-guide/master/eslintrc'; fi; eslint --reset -c eslintrc src/*.js",
+    "lint": "if ! [ -f eslintrc ]; then curl -o eslintrc 'https://raw.githubusercontent.com/ripple/javascript-style-guide/es6/eslintrc'; fi; eslint --reset -c eslintrc src/*.js",
     "perf": "./scripts/perf_test.sh"
   },
   "repository": {
diff --git a/scripts/perf_test.sh b/scripts/perf_test.sh
index 786b68f825..5495d44519 100755
--- a/scripts/perf_test.sh
+++ b/scripts/perf_test.sh
@@ -8,4 +8,4 @@ then
   mkdir -p "$DIR/cache"
   curl -L "$URL" > "$DEST"
 fi
-time node "$DIR/verify_ledger_json.js" "$DEST"
+npm run compile && time node "$DIR/verify_ledger_json.js" "$DEST"
diff --git a/scripts/publish b/scripts/publish
index 4c5761003e..bac4406469 100644
--- a/scripts/publish
+++ b/scripts/publish
@@ -17,15 +17,15 @@ echo "publish to npm"
 npm publish
 exit_on_error
 
-rm -rf dist
+rm -rf dist/bower
 echo ""
 echo "publish to bower"
 
-git clone git@github.com:ripple/bower-ripple.git dist
+git clone git@github.com:ripple/bower-ripple.git dist/bower
 gulp bower
 exit_on_error
 
-cd dist
+cd dist/bower
 version=$(cat bower.json | grep -Eo '([0-9]\.?)+(-rc[0-9])?')
 echo "version: $version"
 git add ripple.js ripple-debug.js ripple-min.js bower.json
@@ -40,4 +40,4 @@ exit_on_error
 git push origin master
 git push --tags origin master
 
-cd ..
\ No newline at end of file
+cd ..
diff --git a/scripts/publish_rc b/scripts/publish_rc
index fd90a92041..dc9f6e41e0 100644
--- a/scripts/publish_rc
+++ b/scripts/publish_rc
@@ -17,15 +17,15 @@ echo "publish rc to npm"
 npm publish --tag beta
 exit_on_error
 
-rm -rf dist
+rm -rf dist/bower
 echo ""
 echo "publish to bower"
 
-git clone git@github.com:ripple/bower-ripple.git dist
+git clone git@github.com:ripple/bower-ripple.git dist/bower
 gulp bower
 exit_on_error
 
-cd dist
+cd dist/bower
 version=$(cat bower.json | grep -Eo '([0-9]\.?)+(-rc[0-9])?')
 echo "version: $version"
 git add ripple.js ripple-debug.js ripple-min.js bower.json
@@ -40,4 +40,4 @@ exit_on_error
 git push origin master
 git push --tags origin master
 
-cd ..
\ No newline at end of file
+cd ..
diff --git a/scripts/publish_to_bower b/scripts/publish_to_bower
index 93ce1d6ea4..280eb6638e 100644
--- a/scripts/publish_to_bower
+++ b/scripts/publish_to_bower
@@ -1,7 +1,7 @@
-rm -rf dist
-git clone git@github.com:ripple/bower-ripple.git dist
+rm -rf dist/bower
+git clone git@github.com:ripple/bower-ripple.git dist/bower
 gulp bower
-cd dist
+cd dist/bower
 version=$(cat bower.json | grep -Eo '([0-9]\.?)+(-rc[0-9])?')
 echo "version: $version"
 git add ripple.js ripple-debug.js ripple-min.js bower.json
@@ -9,4 +9,4 @@ git commit -m "[TASK] add v$version"
 git tag "v$version"
 git push origin master
 git push --tags origin master
-cd ..
\ No newline at end of file
+cd ..
diff --git a/scripts/verify_ledger_json.js b/scripts/verify_ledger_json.js
index ae74aa5661..8f2a5f43f7 100755
--- a/scripts/verify_ledger_json.js
+++ b/scripts/verify_ledger_json.js
@@ -1,8 +1,8 @@
 'use strict';
 
 var fs = require('fs');
-var Amount = require('../src/js/ripple').Amount;
-var Ledger = require('../src/js/ripple/ledger').Ledger;
+var Amount = require('../dist/npm').Amount;
+var Ledger = require('../dist/npm/ledger').Ledger;
 
 function parse_options(from, flags) {
   var argv = from.slice(),
diff --git a/src/request.js b/src/request.js
index 305eb86175..c2329234e3 100644
--- a/src/request.js
+++ b/src/request.js
@@ -542,7 +542,7 @@ Request.prototype.addStream = function(stream, values) {
         break;
     }
   } else if (arguments.length > 1) {
-    for (arg in arguments) {
+    for (var arg in arguments) {
       this.addStream(arguments[arg]);
     }
     return;
diff --git a/test/amount-test.js b/test/amount-test.js
index 7863e727cc..e649908543 100644
--- a/test/amount-test.js
+++ b/test/amount-test.js
@@ -1150,7 +1150,7 @@ describe('Amount', function() {
       var demAmount = Amount.from_json('10/0158415500000000C1F76FF6ECB0BAC600000000/rHb9CJAWyB4rj91VRWn96DkukG4bwdtyTh');
       assert.strictEqual(demAmount.to_text_full(), '10/XAU (-0.5%pa)/rHb9CJAWyB4rj91VRWn96DkukG4bwdtyTh');
       demAmount = demAmount.applyInterest(459990264);
-      assert.strictEqual(demAmount.to_text_full(), '9.294949401870435/XAU (-0.5%pa)/rHb9CJAWyB4rj91VRWn96DkukG4bwdtyTh');
+      assert.strictEqual(demAmount.to_text_full(), '9.294949401870436/XAU (-0.5%pa)/rHb9CJAWyB4rj91VRWn96DkukG4bwdtyTh');
 
     });
     it('from_json apply interest XAU', function() {
@@ -1168,7 +1168,7 @@ describe('Amount', function() {
       var demAmount = Amount.from_json('10/0158415500000000C1F76FF6ECB0BAC600000000/rHb9CJAWyB4rj91VRWn96DkukG4bwdtyTh');
       assert.strictEqual(demAmount.to_human_full(), '10/XAU (-0.5%pa)/rHb9CJAWyB4rj91VRWn96DkukG4bwdtyTh');
       demAmount = demAmount.applyInterest(459990264);
-      assert.strictEqual(demAmount.to_human_full(), '9.294949401870435/XAU (-0.5%pa)/rHb9CJAWyB4rj91VRWn96DkukG4bwdtyTh');
+      assert.strictEqual(demAmount.to_human_full(), '9.294949401870436/XAU (-0.5%pa)/rHb9CJAWyB4rj91VRWn96DkukG4bwdtyTh');
 
     });
     it('from_json apply interest XAU human', function() {
diff --git a/test/currency-test.js b/test/currency-test.js
index 8f1e051187..f41ba20764 100644
--- a/test/currency-test.js
+++ b/test/currency-test.js
@@ -272,7 +272,9 @@ describe('Currency', function() {
       assert.equal(0.995, precision(cur.get_interest_at(new Date(timeUtil.fromRipple(443845330 + 31536000))), 14));
 
       // After one demurrage period, 1/e should have occurred
-      assert.equal(1/Math.E, cur.get_interest_at(443845330 + 6291418827.05));
+      var epsilon = 1e-14;
+      assert(Math.abs(
+        1/Math.E - cur.get_interest_at(443845330 + 6291418827.05)) < epsilon);
 
       // One year before start, it should be (roughly) 0.5% higher.
       assert.equal(1.005, precision(cur.get_interest_at(443845330 - 31536000), 4));
diff --git a/test/ledger-test.js b/test/ledger-test.js
index 1742fb6f28..d9796b98fe 100644
--- a/test/ledger-test.js
+++ b/test/ledger-test.js
@@ -7,7 +7,7 @@ var Ledger = require('ripple-lib').Ledger;
 * @param ledger_index {Number}
 * Expects a corresponding ledger dump in $repo/test/fixtures/ folder
 */
-create_ledger_test = function (ledger_index) {
+var create_ledger_test = function (ledger_index) {
   describe(String(ledger_index), function() {
 
     var path = __dirname + '/fixtures/ledger-full-'+ledger_index+'.json';
diff --git a/test/mocha.opts b/test/mocha.opts
index ccd434ecf5..63a552fe44 100644
--- a/test/mocha.opts
+++ b/test/mocha.opts
@@ -1 +1 @@
---reporter spec --timeout 10000 --slow 500
+--reporter spec --timeout 10000 --slow 500 --compilers js:babel/register
diff --git a/test/request-test.js b/test/request-test.js
index aefd1cc043..1f6e339aea 100644
--- a/test/request-test.js
+++ b/test/request-test.js
@@ -510,7 +510,7 @@ describe('Request', function() {
 
   it('Timeout', function(done) {
     var server = makeServer('wss://localhost:5006');
-    var successEmited = false;
+    var successEmitted = false;
 
     server._request = function(req) {
       assert(req instanceof Request);
@@ -542,7 +542,7 @@ describe('Request', function() {
 
   it('Timeout - satisfied', function(done) {
     var server = makeServer('wss://localhost:5006');
-    var successEmited = false;
+    var successEmitted = false;
 
     server._request = function(req) {
       assert(req instanceof Request);