diff --git a/.flowconfig b/.flowconfig
index bad57bc52f6..5cfdb69fa30 100644
--- a/.flowconfig
+++ b/.flowconfig
@@ -7,6 +7,7 @@
 <PROJECT_ROOT>/.*/__tests__/.*
 
 # Ignore Docs
+<PROJECT_ROOT>/docs/.*
 <PROJECT_ROOT>/.*/docs/.*
 
 [include]
diff --git a/circle.yml b/circle.yml
new file mode 100644
index 00000000000..3b8e1bb3fa4
--- /dev/null
+++ b/circle.yml
@@ -0,0 +1,42 @@
+---
+general:
+  branches:
+    ignore:
+      - gh-pages
+
+machine:
+  timezone: America/Los_Angeles
+  node:
+    version: 6
+  ruby:
+    version: 2.2.3
+  environment:
+    TRAVIS_REPO_SLUG: facebook/react
+
+dependencies:
+  pre:
+    # This is equivalent to $TRAVIS_COMMIT_RANGE
+    # Need to figure out how to bail early if this is a "docs only" build
+    - echo $CIRCLE_COMPARE_URL | cut -d/ -f7
+  override:
+    - bundle install --gemfile=docs/Gemfile --deployment --path=vendor/bundle --jobs=3 --retry=3
+    - npm install
+    - scripts/circleci/set_up_github_keys.sh
+  post:
+    # - npm ls --depth=0
+  cache_directories:
+    - docs/vendor/bundle
+    - .grunt # Show size comparisons between builds
+    - ~/react-gh-pages # docs checkout
+
+test:
+  override:
+    - ./scripts/circleci/test_entry_point.sh:
+        parallel: true
+
+deployment:
+  staging:
+    branch: /.*/
+    commands:
+      - ./scripts/circleci/upload_build.sh
+      - ./scripts/circleci/build_gh_pages.sh
diff --git a/fixtures/browserify/input.js b/fixtures/browserify/input.js
index da6cc5d0ff1..4ab5502dd32 100644
--- a/fixtures/browserify/input.js
+++ b/fixtures/browserify/input.js
@@ -1,3 +1,5 @@
+'use strict';
+
 var React = require('react');
 var CSSTransitionGroup = require('react-addons-css-transition-group');
 var ReactDOM = require('react-dom');
diff --git a/fixtures/brunch/app/initialize.js b/fixtures/brunch/app/initialize.js
index da6cc5d0ff1..4ab5502dd32 100644
--- a/fixtures/brunch/app/initialize.js
+++ b/fixtures/brunch/app/initialize.js
@@ -1,3 +1,5 @@
+'use strict';
+
 var React = require('react');
 var CSSTransitionGroup = require('react-addons-css-transition-group');
 var ReactDOM = require('react-dom');
diff --git a/fixtures/brunch/config.js b/fixtures/brunch/config.js
index ba12fc72c23..c8733fdb678 100644
--- a/fixtures/brunch/config.js
+++ b/fixtures/brunch/config.js
@@ -1,3 +1,5 @@
+'use strict';
+
 exports.config = {
   paths: {
     public: '.',
diff --git a/fixtures/brunch/input.js b/fixtures/brunch/input.js
index da6cc5d0ff1..4ab5502dd32 100644
--- a/fixtures/brunch/input.js
+++ b/fixtures/brunch/input.js
@@ -1,3 +1,5 @@
+'use strict';
+
 var React = require('react');
 var CSSTransitionGroup = require('react-addons-css-transition-group');
 var ReactDOM = require('react-dom');
diff --git a/fixtures/build-all.js b/fixtures/build-all.js
index b5620c0fa32..84b8decc3bc 100644
--- a/fixtures/build-all.js
+++ b/fixtures/build-all.js
@@ -1,3 +1,5 @@
+'use strict';
+
 var fs = require('fs');
 var path = require('path');
 var { spawnSync } = require('child_process');
diff --git a/fixtures/rjs/config.js b/fixtures/rjs/config.js
index f15dc110035..20d2d32b93e 100644
--- a/fixtures/rjs/config.js
+++ b/fixtures/rjs/config.js
@@ -1,3 +1,5 @@
+'use strict';
+
 module.exports = {
   baseUrl: '.',
   name: 'input',
diff --git a/fixtures/rjs/input.js b/fixtures/rjs/input.js
index 2b0deee96c2..cbda88d7ef6 100644
--- a/fixtures/rjs/input.js
+++ b/fixtures/rjs/input.js
@@ -1,3 +1,5 @@
+'use strict';
+
 require(['react', 'react-dom'], function(React, ReactDOM) {
   var CSSTransitionGroup = React.addons.CSSTransitionGroup;
   ReactDOM.render(
diff --git a/fixtures/systemjs-builder/build.js b/fixtures/systemjs-builder/build.js
index d476c09a646..c596c882c3a 100644
--- a/fixtures/systemjs-builder/build.js
+++ b/fixtures/systemjs-builder/build.js
@@ -1,3 +1,5 @@
+'use strict';
+
 var Builder = require('systemjs-builder');
 
 var builder = new Builder('/', './config.js');
diff --git a/fixtures/systemjs-builder/config.js b/fixtures/systemjs-builder/config.js
index baed2db8c62..1fcfe2d2b7c 100644
--- a/fixtures/systemjs-builder/config.js
+++ b/fixtures/systemjs-builder/config.js
@@ -1,3 +1,5 @@
+'use strict';
+
 System.config({
   paths: {
     react: '../../build/react-with-addons.js',
diff --git a/fixtures/systemjs-builder/input.js b/fixtures/systemjs-builder/input.js
index 27d5c10086c..78e914c5517 100644
--- a/fixtures/systemjs-builder/input.js
+++ b/fixtures/systemjs-builder/input.js
@@ -1,3 +1,5 @@
+'use strict';
+
 import React from 'react';
 import ReactDOM from 'react-dom';
 
diff --git a/fixtures/webpack-alias/config.js b/fixtures/webpack-alias/config.js
index dcc0c3a9072..7ba98467a5f 100644
--- a/fixtures/webpack-alias/config.js
+++ b/fixtures/webpack-alias/config.js
@@ -1,3 +1,5 @@
+'use strict';
+
 module.exports = {
   entry: './input',
   output: {
diff --git a/fixtures/webpack-alias/input.js b/fixtures/webpack-alias/input.js
index f1e2d79e23c..57b7e94cc90 100644
--- a/fixtures/webpack-alias/input.js
+++ b/fixtures/webpack-alias/input.js
@@ -1,3 +1,5 @@
+'use strict';
+
 var React = require('react');
 var ReactDOM = require('react-dom');
 
diff --git a/fixtures/webpack/config.js b/fixtures/webpack/config.js
index 685cac24ee9..e00ada05a6c 100644
--- a/fixtures/webpack/config.js
+++ b/fixtures/webpack/config.js
@@ -1,3 +1,5 @@
+'use strict';
+
 module.exports = {
   entry: './input',
   output: {
diff --git a/fixtures/webpack/input.js b/fixtures/webpack/input.js
index da6cc5d0ff1..4ab5502dd32 100644
--- a/fixtures/webpack/input.js
+++ b/fixtures/webpack/input.js
@@ -1,3 +1,5 @@
+'use strict';
+
 var React = require('react');
 var CSSTransitionGroup = require('react-addons-css-transition-group');
 var ReactDOM = require('react-dom');
diff --git a/grunt/tasks/jest.js b/grunt/tasks/jest.js
index d48d6f1f0c3..7bccf5dfe72 100644
--- a/grunt/tasks/jest.js
+++ b/grunt/tasks/jest.js
@@ -8,6 +8,7 @@ function run(done, coverage) {
 
   var args = [
     path.join('node_modules', 'jest', 'bin', 'jest'),
+    '--runInBand',
   ];
   if (coverage) {
     args.push('--coverage');
diff --git a/package.json b/package.json
index 8f16f2b36c7..737754e0f30 100644
--- a/package.json
+++ b/package.json
@@ -58,6 +58,7 @@
     "gulp-util": "^3.0.7",
     "gzip-js": "~0.3.2",
     "jest": "^15.1.1",
+    "jest-cli": "^15.1.1",
     "loose-envify": "^1.1.0",
     "merge-stream": "^1.0.0",
     "object-assign": "^4.1.0",
diff --git a/scripts/circleci/build_gh_pages.sh b/scripts/circleci/build_gh_pages.sh
new file mode 100755
index 00000000000..fcf49f2af95
--- /dev/null
+++ b/scripts/circleci/build_gh_pages.sh
@@ -0,0 +1,33 @@
+#!/bin/bash
+
+set -e
+
+if [ -z $CI_PULL_REQUEST ] && [ "$CIRCLE_BRANCH" = "$REACT_WEBSITE_BRANCH" ]; then
+
+  GH_PAGES_DIR=`pwd`/../react-gh-pages
+
+  # check if directory exists (restored from cache)
+  if [ -d $GH_PAGES_DIR ]; then
+    pushd $GH_PAGES_DIR
+    git pull origin gh-pages
+    popd
+  else
+    git clone --branch gh-pages --depth=1 \
+      https://reactjs-bot@github.com/facebook/react.git \
+      $GH_PAGES_DIR
+  fi
+
+  pushd docs
+  bundle exec rake release
+  cd $GH_PAGES_DIR
+  git status
+  git --no-pager diff
+  if ! git diff-index --quiet HEAD --; then
+    git add -A .
+    git commit -m "Rebuild website"
+    git push origin gh-pages
+  fi
+  popd
+else
+  echo "Not building website"
+fi
diff --git a/scripts/circleci/set_up_github_keys.sh b/scripts/circleci/set_up_github_keys.sh
new file mode 100755
index 00000000000..302c40eef0e
--- /dev/null
+++ b/scripts/circleci/set_up_github_keys.sh
@@ -0,0 +1,12 @@
+#!/bin/bash
+
+set -e
+
+if [ -n $GITHUB_TOKEN ]; then
+
+  GH_PAGES_DIR=`pwd`/../react-gh-pages
+  echo "machine github.com login reactjs-bot password $GITHUB_TOKEN" >~/.netrc
+  git config --global user.name "Circle CI"
+  git config --global user.email "circle@reactjs.org"
+
+fi
diff --git a/scripts/circleci/test_coverage.sh b/scripts/circleci/test_coverage.sh
new file mode 100755
index 00000000000..05a717c2a41
--- /dev/null
+++ b/scripts/circleci/test_coverage.sh
@@ -0,0 +1,8 @@
+#!/bin/bash
+
+set -e
+
+./node_modules/.bin/grunt jest:coverage
+if [ -z $CI_PULL_REQUEST ]; then
+  cat ./coverage/lcov.info | ./node_modules/.bin/coveralls
+fi
diff --git a/scripts/circleci/test_entry_point.sh b/scripts/circleci/test_entry_point.sh
new file mode 100755
index 00000000000..2f9c042f7e8
--- /dev/null
+++ b/scripts/circleci/test_entry_point.sh
@@ -0,0 +1,62 @@
+#!/bin/bash
+
+set -e
+
+COMMANDS_TO_RUN=()
+
+# We split these to be approximately equal chunks of four. As of this writing,
+# times were around:
+# - 3:30 test_coverage.sh
+# - 2:00 test_fiber.sh
+# - 1:15 test_html_generation.sh
+# - 1:15 grunt build
+# with everything else < 0:30.
+
+if [ $((1 % CIRCLE_NODE_TOTAL)) -eq "$CIRCLE_NODE_INDEX" ]; then
+  COMMANDS_TO_RUN+=('./scripts/circleci/test_coverage.sh')
+fi
+
+if [ $((2 % CIRCLE_NODE_TOTAL)) -eq "$CIRCLE_NODE_INDEX" ]; then
+  COMMANDS_TO_RUN+=('./scripts/circleci/test_html_generation.sh')
+fi
+
+# These seem out of order but extract-errors must be run after jest.
+if [ $((0 % CIRCLE_NODE_TOTAL)) -eq "$CIRCLE_NODE_INDEX" ]; then
+  COMMANDS_TO_RUN+=('./node_modules/.bin/gulp lint')
+  COMMANDS_TO_RUN+=('./node_modules/.bin/gulp flow')
+  COMMANDS_TO_RUN+=('./node_modules/.bin/grunt build')
+  COMMANDS_TO_RUN+=('./scripts/circleci/test_extract_errors.sh')
+  COMMANDS_TO_RUN+=('./scripts/circleci/track_stats.sh')
+fi
+
+RETURN_CODES=()
+FAILURE=0
+
+printf "Node #%s (%s total). " "$CIRCLE_NODE_INDEX" "$CIRCLE_NODE_TOTAL"
+if [ -n "${COMMANDS_TO_RUN[0]}" ]; then
+  echo "Preparing to run commands:"
+  for cmd in "${COMMANDS_TO_RUN[@]}"; do
+    echo "- $cmd"
+  done
+
+  for cmd in "${COMMANDS_TO_RUN[@]}"; do
+    echo
+    echo "$ $cmd"
+    set +e
+    $cmd
+    rc=$?
+    set -e
+    RETURN_CODES+=($rc)
+    if [ $rc -ne 0 ]; then
+      FAILURE=$rc
+    fi
+  done
+
+  echo
+  for i in "${!COMMANDS_TO_RUN[@]}"; do
+    echo "Received return code ${RETURN_CODES[i]} from: ${COMMANDS_TO_RUN[i]}"
+  done
+  exit $FAILURE
+else
+  echo "No commands to run."
+fi
diff --git a/scripts/circleci/test_extract_errors.sh b/scripts/circleci/test_extract_errors.sh
new file mode 100755
index 00000000000..5169752509e
--- /dev/null
+++ b/scripts/circleci/test_extract_errors.sh
@@ -0,0 +1,6 @@
+#!/bin/bash
+
+set -e
+
+./node_modules/.bin/gulp react:extract-errors
+git checkout -- scripts/error-codes/codes.json
diff --git a/scripts/circleci/test_html_generation.sh b/scripts/circleci/test_html_generation.sh
new file mode 100755
index 00000000000..0bedb26aea4
--- /dev/null
+++ b/scripts/circleci/test_html_generation.sh
@@ -0,0 +1,9 @@
+#!/bin/bash
+
+set -e
+
+echo 'Testing in server-render (HTML generation) mode...'
+printf '\nmodule.exports.useCreateElement = false;\n' \
+  >> src/renderers/dom/shared/ReactDOMFeatureFlags.js
+./node_modules/.bin/grunt jest:normal
+git checkout -- src/renderers/dom/shared/ReactDOMFeatureFlags.js
diff --git a/scripts/circleci/track_stats.sh b/scripts/circleci/track_stats.sh
new file mode 100755
index 00000000000..a8a3eae1fad
--- /dev/null
+++ b/scripts/circleci/track_stats.sh
@@ -0,0 +1,8 @@
+#!/bin/bash
+
+set -e
+
+ALL_FILES=`find src -name '*.js' | grep -v umd/ | grep -v __tests__ | grep -v __mocks__`
+COUNT_ALL_FILES=`echo "$ALL_FILES" | wc -l`
+COUNT_WITH_FLOW=`grep '@flow' $ALL_FILES | perl -pe 's/:.+//' | wc -l`
+node scripts/facts-tracker/index.js "flow-files" "$COUNT_WITH_FLOW/$COUNT_ALL_FILES"
diff --git a/scripts/circleci/upload_build.sh b/scripts/circleci/upload_build.sh
new file mode 100755
index 00000000000..0558ba8dd05
--- /dev/null
+++ b/scripts/circleci/upload_build.sh
@@ -0,0 +1,23 @@
+#!/bin/bash
+
+set -e
+
+if [ -z $CI_PULL_REQUEST ] && [ -n "$BUILD_SERVER_ENDPOINT" ]; then
+  curl \
+    -F "react=@build/react.js" \
+    -F "react.min=@build/react.min.js" \
+    -F "react-with-addons=@build/react-with-addons.js" \
+    -F "react-with-addons.min=@build/react-with-addons.min.js" \
+    -F "react-dom=@build/react-dom.js" \
+    -F "react-dom.min=@build/react-dom.min.js" \
+    -F "react-dom-server=@build/react-dom-server.js" \
+    -F "react-dom-server.min=@build/react-dom-server.min.js" \
+    -F "npm-react=@build/packages/react.tgz" \
+    -F "npm-react-dom=@build/packages/react-dom.tgz" \
+    -F "commit=$CIRCLE_SHA1" \
+    -F "date=`git log --format='%ct' -1`" \
+    -F "pull_request=false" \
+    -F "token=$BUILD_SERVER_TOKEN" \
+    -F "branch=$CIRCLE_BRANCH" \
+    $BUILD_SERVER_ENDPOINT
+fi