diff --git a/.travis.yml b/.travis.yml
index 167fc436b..551340900 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -1,13 +1,9 @@
 ---
-# Use Ubuntu Precise instead of new default Trusty which cause build fail
-# with pre installed yarn v0.17.8
-# https://github.com/facebookincubator/create-react-app/issues/3054
-# TODO: remove after Trusty environment is updated with a lastet version of yarn
-dist: precise
+dist: trusty
 language: node_js
 node_js:
-  - 6
   - 8
+  - 9
 cache:
   directories:
   - node_modules
@@ -16,13 +12,17 @@ cache:
 install: true
 script:
  - 'if [ $TEST_SUITE = "simple" ]; then tasks/e2e-simple.sh; fi'
+ - 'if [ $TEST_SUITE = "kitchensink" ]; then tasks/e2e-kitchensink.sh; fi'
+ - 'if [ $TEST_SUITE = "old-node" ]; then tasks/e2e-old-node.sh; fi'
+ # Disabled for the moment, since it requires additional work to be done.
+ # - 'if [ $TEST_SUITE = "installs" ]; then tasks/e2e-installs.sh; fi'
 env:
-  global:
-    - USE_YARN=no
   matrix:
     - TEST_SUITE=simple
-    - TEST_SUITE=install
-# There's a weird Yarn/Lerna bug related to prerelease versions.
-# TODO: reenable after we ship 1.0.
-#    - node_js: 6
-#      env: USE_YARN=yes TEST_SUITE=simple
+    - TEST_SUITE=kitchensink
+    # See comment above
+    # - TEST_SUITE=installs
+matrix:
+  include:
+    - node_js: 6
+      env: TEST_SUITE=kitchensink
\ No newline at end of file
diff --git a/package.json b/package.json
index 596eaa1ad..e02a51dba 100644
--- a/package.json
+++ b/package.json
@@ -1,16 +1,19 @@
 {
   "private": true,
+  "workspaces": [
+    "packages/*"
+  ],
   "scripts": {
-    "build": "node packages/react-scripts/scripts/build.js",
+    "build": "cd packages/react-scripts && node scripts/build.js",
     "changelog": "lerna-changelog",
-    "create-react-app": "tasks/cra.sh",
+    "create-react-app": "node tasks/cra.js",
     "e2e": "tasks/e2e-simple.sh",
     "e2e:docker": "tasks/local-test.sh",
-    "postinstall": "node bootstrap.js && cd packages/react-error-overlay/ && npm run build:prod",
-    "publish": "tasks/release.sh",
-    "start": "node packages/react-scripts/scripts/start.js",
-    "test": "node packages/react-scripts/scripts/test.js --env=jsdom",
-    "format": "prettier --trailing-comma es5 --single-quote --write \"packages/*/*.js\" \"packages/*/!(node_modules)/**/*.js\"",
+    "postinstall": "cd packages/react-error-overlay/ && yarn build:prod",
+    "publish": "tasks/publish.sh",
+    "start": "cd packages/react-scripts && node scripts/start.js",
+    "test": "cd packages/react-scripts && node scripts/test.js --env=jsdom",
+    "format": "prettier --trailing-comma es5 --single-quote --write 'packages/*/*.js' 'packages/*/!(node_modules)/**/*.js'",
     "precommit": "lint-staged"
   },
   "devDependencies": {
@@ -20,10 +23,10 @@
     "@types/react-dom": "^15.5.0",
     "eslint": "^4.4.1",
     "husky": "^0.13.2",
-    "lerna": "^2.0.0",
+    "lerna": "2.6.0",
     "lerna-changelog": "^0.6.0",
     "lint-staged": "^3.3.1",
-    "prettier": "^1.5.2"
+    "prettier": "1.6.1"
   },
   "lint-staged": {
     "*.js": [
diff --git a/packages/react-dev-utils/package.json b/packages/react-dev-utils/package.json
index 8adff62fa..eab07c1be 100644
--- a/packages/react-dev-utils/package.json
+++ b/packages/react-dev-utils/package.json
@@ -56,7 +56,7 @@
     "text-table": "0.2.0"
   },
   "devDependencies": {
-    "jest": "20.0.4"
+    "jest": "22.4.2"
   },
   "scripts": {
     "test": "jest"
diff --git a/packages/react-error-overlay/package.json b/packages/react-error-overlay/package.json
index 87099dd5e..fe6c7fd68 100644
--- a/packages/react-error-overlay/package.json
+++ b/packages/react-error-overlay/package.json
@@ -48,7 +48,7 @@
     "eslint-plugin-react": "7.1.0",
     "flow-bin": "^0.63.1",
     "html-entities": "1.2.1",
-    "jest": "20.0.4",
+    "jest": "22.4.2",
     "jest-fetch-mock": "1.2.1",
     "object-assign": "4.1.1",
     "promise": "8.0.1",
diff --git a/packages/react-scripts/package.json b/packages/react-scripts/package.json
index 46d9cbee4..131ba2997 100644
--- a/packages/react-scripts/package.json
+++ b/packages/react-scripts/package.json
@@ -35,7 +35,7 @@
     "fork-ts-checker-webpack-plugin": "^0.2.8",
     "fs-extra": "3.0.1",
     "html-webpack-plugin": "2.29.0",
-    "jest": "22.1.4",
+    "jest": "22.4.2",
     "object-assign": "4.1.1",
     "postcss-flexbugs-fixes": "3.2.0",
     "postcss-loader": "2.0.8",
diff --git a/tasks/e2e-installs.sh b/tasks/e2e-installs.sh
index f352a5448..d1150a874 100755
--- a/tasks/e2e-installs.sh
+++ b/tasks/e2e-installs.sh
@@ -14,13 +14,17 @@ cd "$(dirname "$0")"
 
 # CLI and app temporary locations
 # http://unix.stackexchange.com/a/84980
-temp_cli_path=`mktemp -d 2>/dev/null || mktemp -d -t 'temp_cli_path'`
 temp_app_path=`mktemp -d 2>/dev/null || mktemp -d -t 'temp_app_path'`
+custom_registry_url=http://localhost:4873
+original_npm_registry_url=`npm get registry`
+original_yarn_registry_url=`yarn config get registry`
 
 function cleanup {
   echo 'Cleaning up.'
   cd "$root_path"
-  rm -rf "$temp_cli_path" "$temp_app_path"
+  rm -rf "$temp_app_path"
+  npm set registry "$original_npm_registry_url"
+  yarn config set registry "$original_yarn_registry_url"
 }
 
 # Error messages are redirected to stderr
@@ -55,10 +59,6 @@ function checkDependencies {
   fi
 }
 
-function create_react_app {
-  node "$temp_cli_path"/node_modules/create-react-app/index.js $*
-}
-
 # Exit the script with a helpful error message when any error is encountered
 trap 'set +x; handle_error $LINENO $BASH_COMMAND' ERR
 
@@ -72,77 +72,61 @@ set -x
 cd ..
 root_path=$PWD
 
-# Clear cache to avoid issues with incorrect packages being used
-if hash yarnpkg 2>/dev/null
-then
-  # AppVeyor uses an old version of yarn.
-  # Once updated to 0.24.3 or above, the workaround can be removed
-  # and replaced with `yarnpkg cache clean`
-  # Issues:
-  #    https://github.com/yarnpkg/yarn/issues/2591
-  #    https://github.com/appveyor/ci/issues/1576
-  #    https://github.com/facebookincubator/create-react-app/pull/2400
-  # When removing workaround, you may run into
-  #    https://github.com/facebookincubator/create-react-app/issues/2030
-  case "$(uname -s)" in
-    *CYGWIN*|MSYS*|MINGW*) yarn=yarn.cmd;;
-    *) yarn=yarnpkg;;
-  esac
-  $yarn cache clean
-fi
-
 if hash npm 2>/dev/null
 then
-  # npm 5 is too buggy right now
-  if [ $(npm -v | head -c 1) -eq 5 ]; then
-    npm i -g npm@^4.x
-  fi;
+  npm i -g npm@latest
   npm cache clean || npm cache verify
 fi
 
-# Prevent bootstrap, we only want top-level dependencies
-cp package.json package.json.bak
-grep -v "postinstall" package.json > temp && mv temp package.json
-npm install
-mv package.json.bak package.json
+# Bootstrap monorepo
+yarn
 
-if [ "$USE_YARN" = "yes" ]
-then
-  # Install Yarn so that the test can use it to install packages.
-  npm install -g yarn
-  yarn cache clean
-fi
+# ******************************************************************************
+# First, publish the monorepo.
+# ******************************************************************************
+
+# Start local registry
+tmp_registry_log=`mktemp`
+nohup npx verdaccio@2.7.2 &>$tmp_registry_log &
+# Wait for `verdaccio` to boot
+grep -q 'http address' <(tail -f $tmp_registry_log)
 
-# We removed the postinstall, so do it manually
-node bootstrap.js
+# Set registry to local registry
+npm set registry "$custom_registry_url"
+yarn config set registry "$custom_registry_url"
 
-cd packages/react-error-overlay/
-npm run build:prod
-cd ../..
+# Login so we can publish packages
+npx npm-cli-login@0.0.10 -u user -p password -e user@example.com -r "$custom_registry_url" --quotes
+
+# Publish the monorepo
+git clean -df
+./tasks/publish.sh --yes --force-publish=* --skip-git --cd-version=prerelease --exact --npm-tag=latest
 
 # ******************************************************************************
-# First, pack and install create-react-app.
+# Test --scripts-version with a version number
 # ******************************************************************************
 
-# Pack CLI
-cd "$root_path"/packages/create-react-app
-cli_path=$PWD/`npm pack`
+cd "$temp_app_path"
+npx create-react-app --scripts-version=1.0.17 test-app-version-number
+cd test-app-version-number
 
-# Install the CLI in a temporary location
-cd "$temp_cli_path"
-npm install "$cli_path"
+# Check corresponding scripts version is installed.
+exists node_modules/react-scripts
+grep '"version": "1.0.17"' node_modules/react-scripts/package.json
+checkDependencies
 
 # ******************************************************************************
-# Test --scripts-version with a version number
+# Test --use-npm flag
 # ******************************************************************************
 
 cd "$temp_app_path"
-create_react_app --scripts-version=0.4.0 test-app-version-number
-cd test-app-version-number
+npx create-react-app --use-npm --scripts-version=1.0.17 test-use-npm-flag
+cd test-use-npm-flag
 
 # Check corresponding scripts version is installed.
 exists node_modules/react-scripts
-grep '"version": "0.4.0"' node_modules/react-scripts/package.json
+[ ! -e "yarn.lock" ] && echo "yarn.lock correctly does not exist"
+grep '"version": "1.0.17"' node_modules/react-scripts/package.json
 checkDependencies
 
 # ******************************************************************************
@@ -150,12 +134,12 @@ checkDependencies
 # ******************************************************************************
 
 cd "$temp_app_path"
-create_react_app --scripts-version=https://registry.npmjs.org/react-scripts/-/react-scripts-0.4.0.tgz test-app-tarball-url
+npx create-react-app --scripts-version=https://registry.npmjs.org/react-scripts/-/react-scripts-1.0.17.tgz test-app-tarball-url
 cd test-app-tarball-url
 
 # Check corresponding scripts version is installed.
 exists node_modules/react-scripts
-grep '"version": "0.4.0"' node_modules/react-scripts/package.json
+grep '"version": "1.0.17"' node_modules/react-scripts/package.json
 checkDependencies
 
 # ******************************************************************************
@@ -163,7 +147,7 @@ checkDependencies
 # ******************************************************************************
 
 cd "$temp_app_path"
-create_react_app --scripts-version=react-scripts-fork test-app-fork
+npx create-react-app --scripts-version=react-scripts-fork test-app-fork
 cd test-app-fork
 
 # Check corresponding scripts version is installed.
@@ -175,7 +159,7 @@ exists node_modules/react-scripts-fork
 
 cd "$temp_app_path"
 # we will install a non-existing package to simulate a failed installataion.
-create_react_app --scripts-version=`date +%s` test-app-should-not-exist || true
+npx create-react-app --scripts-version=`date +%s` test-app-should-not-exist || true
 # confirm that the project folder was deleted
 test ! -d test-app-should-not-exist
 
@@ -187,7 +171,7 @@ cd "$temp_app_path"
 mkdir test-app-should-remain
 echo '## Hello' > ./test-app-should-remain/README.md
 # we will install a non-existing package to simulate a failed installataion.
-create_react_app --scripts-version=`date +%s` test-app-should-remain || true
+npx create-react-app --scripts-version=`date +%s` test-app-should-remain || true
 # confirm the file exist
 test -e test-app-should-remain/README.md
 # confirm only README.md is the only file in the directory
@@ -201,7 +185,7 @@ fi
 
 cd $temp_app_path
 curl "https://registry.npmjs.org/@enoah_netzach/react-scripts/-/react-scripts-0.9.0.tgz" -o enoah-scripts-0.9.0.tgz
-create_react_app --scripts-version=$temp_app_path/enoah-scripts-0.9.0.tgz test-app-scoped-fork-tgz
+npx create-react-app --scripts-version=$temp_app_path/enoah-scripts-0.9.0.tgz test-app-scoped-fork-tgz
 cd test-app-scoped-fork-tgz
 
 # Check corresponding scripts version is installed.
@@ -216,22 +200,22 @@ cd "$temp_app_path"
 mkdir test-app-nested-paths-t1
 cd test-app-nested-paths-t1
 mkdir -p test-app-nested-paths-t1/aa/bb/cc/dd
-create_react_app test-app-nested-paths-t1/aa/bb/cc/dd
+npx create-react-app test-app-nested-paths-t1/aa/bb/cc/dd
 cd test-app-nested-paths-t1/aa/bb/cc/dd
-npm start -- --smoke-test
+yarn start --smoke-test
 
 # Testing a path that does not exist
 cd "$temp_app_path"
-create_react_app test-app-nested-paths-t2/aa/bb/cc/dd
+npx create-react-app test-app-nested-paths-t2/aa/bb/cc/dd
 cd test-app-nested-paths-t2/aa/bb/cc/dd
-npm start -- --smoke-test
+yarn start --smoke-test
 
 # Testing a path that is half exists
 cd "$temp_app_path"
 mkdir -p test-app-nested-paths-t3/aa
-create_react_app test-app-nested-paths-t3/aa/bb/cc/dd
+npx create-react-app test-app-nested-paths-t3/aa/bb/cc/dd
 cd test-app-nested-paths-t3/aa/bb/cc/dd
-npm start -- --smoke-test
+yarn start --smoke-test
 
 # Cleanup
-cleanup
+cleanup
\ No newline at end of file
diff --git a/tasks/e2e-kitchensink.sh b/tasks/e2e-kitchensink.sh
index c1167c1de..1aa55a907 100755
--- a/tasks/e2e-kitchensink.sh
+++ b/tasks/e2e-kitchensink.sh
@@ -14,16 +14,20 @@ cd "$(dirname "$0")"
 
 # CLI, app, and test module temporary locations
 # http://unix.stackexchange.com/a/84980
-temp_cli_path=`mktemp -d 2>/dev/null || mktemp -d -t 'temp_cli_path'`
 temp_app_path=`mktemp -d 2>/dev/null || mktemp -d -t 'temp_app_path'`
 temp_module_path=`mktemp -d 2>/dev/null || mktemp -d -t 'temp_module_path'`
+custom_registry_url=http://localhost:4873
+original_npm_registry_url=`npm get registry`
+original_yarn_registry_url=`yarn config get registry`
 
 function cleanup {
   echo 'Cleaning up.'
   ps -ef | grep 'react-scripts' | grep -v grep | awk '{print $2}' | xargs kill -9
   cd "$root_path"
   # TODO: fix "Device or resource busy" and remove ``|| $CI`
-  rm -rf "$temp_cli_path" "$temp_app_path" "$temp_module_path" || $CI
+  rm -rf "$temp_app_path" "$temp_module_path" || $CI
+  npm set registry "$original_npm_registry_url"
+  yarn config set registry "$original_yarn_registry_url"
 }
 
 # Error messages are redirected to stderr
@@ -40,35 +44,6 @@ function handle_exit {
   exit
 }
 
-function create_react_app {
-  node "$temp_cli_path"/node_modules/create-react-app/index.js "$@"
-}
-
-function install_package {
-  local pkg=$(basename $1)
-
-  # Clean target (for safety)
-  rm -rf node_modules/$pkg/
-  rm -rf node_modules/**/$pkg/
-
-  # Copy package into node_modules/ ignoring installed deps
-  # rsync -a ${1%/} node_modules/ --exclude node_modules
-  cp -R ${1%/} node_modules/
-  rm -rf node_modules/$pkg/node_modules/
-
-  # Install `dependencies`
-  cd node_modules/$pkg/
-  if [ "$USE_YARN" = "yes" ]
-  then
-    yarn install --production
-  else
-    npm install --only=production
-  fi
-  # Remove our packages to ensure side-by-side versions are used (which we link)
-  rm -rf node_modules/{babel-preset-react-app,eslint-config-react-app,react-dev-utils,react-error-overlay,react-scripts}
-  cd ../..
-}
-
 # Check for the existence of one or more files.
 function exists {
   for f in $*; do
@@ -89,94 +64,47 @@ set -x
 cd ..
 root_path=$PWD
 
-# Clear cache to avoid issues with incorrect packages being used
-if hash yarnpkg 2>/dev/null
-then
-  # AppVeyor uses an old version of yarn.
-  # Once updated to 0.24.3 or above, the workaround can be removed
-  # and replaced with `yarnpkg cache clean`
-  # Issues:
-  #    https://github.com/yarnpkg/yarn/issues/2591
-  #    https://github.com/appveyor/ci/issues/1576
-  #    https://github.com/facebookincubator/create-react-app/pull/2400
-  # When removing workaround, you may run into
-  #    https://github.com/facebookincubator/create-react-app/issues/2030
-  case "$(uname -s)" in
-    *CYGWIN*|MSYS*|MINGW*) yarn=yarn.cmd;;
-    *) yarn=yarnpkg;;
-  esac
-  $yarn cache clean
-fi
-
 if hash npm 2>/dev/null
 then
-  # npm 5 is too buggy right now
-  if [ $(npm -v | head -c 1) -eq 5 ]; then
-    npm i -g npm@^4.x
-  fi;
+  npm i -g npm@latest
   npm cache clean || npm cache verify
 fi
 
-# Prevent bootstrap, we only want top-level dependencies
-cp package.json package.json.bak
-grep -v "postinstall" package.json > temp && mv temp package.json
-npm install
-mv package.json.bak package.json
-
-if [ "$USE_YARN" = "yes" ]
-then
-  # Install Yarn so that the test can use it to install packages.
-  npm install -g yarn
-  yarn cache clean
-fi
-
-# We removed the postinstall, so do it manually
-node bootstrap.js
-
-cd packages/react-error-overlay/
-npm run build:prod
-cd ../..
+# Bootstrap monorepo
+yarn
 
 # ******************************************************************************
-# First, pack react-scripts and create-react-app so we can use them.
+# First, publish the monorepo.
 # ******************************************************************************
 
-# Pack CLI
-cd "$root_path"/packages/create-react-app
-cli_path=$PWD/`npm pack`
-
-# Go to react-scripts
-cd "$root_path"/packages/react-scripts
+# Start local registry
+tmp_registry_log=`mktemp`
+nohup npx verdaccio@2.7.2 &>$tmp_registry_log &
+# Wait for `verdaccio` to boot
+grep -q 'http address' <(tail -f $tmp_registry_log)
 
-# Save package.json because we're going to touch it
-cp package.json package.json.orig
+# Set registry to local registry
+npm set registry "$custom_registry_url"
+yarn config set registry "$custom_registry_url"
 
-# Replace own dependencies (those in the `packages` dir) with the local paths
-# of those packages.
-node "$root_path"/tasks/replace-own-deps.js
+# Login so we can publish packages
+npx npm-cli-login@0.0.10 -u user -p password -e user@example.com -r "$custom_registry_url" --quotes
 
-# Finally, pack react-scripts
-scripts_path="$root_path"/packages/react-scripts/`npm pack`
-
-# Restore package.json
-rm package.json
-mv package.json.orig package.json
+# Publish the monorepo
+git clean -df
+./tasks/publish.sh --yes --force-publish=* --skip-git --cd-version=prerelease --exact --npm-tag=latest
 
 # ******************************************************************************
-# Now that we have packed them, create a clean app folder and install them.
+# Now that we have published them, create a clean app folder and install them.
 # ******************************************************************************
 
-# Install the CLI in a temporary location
-cd "$temp_cli_path"
-npm install "$cli_path"
-
 # Install the app in a temporary location
 cd $temp_app_path
-create_react_app --scripts-version="$scripts_path" --internal-testing-template="$root_path"/packages/react-scripts/fixtures/kitchensink test-kitchensink
+npx create-react-app --internal-testing-template="$root_path"/packages/react-scripts/fixtures/kitchensink test-kitchensink
 
 # Install the test module
 cd "$temp_module_path"
-npm install test-integrity@^2.0.1
+yarn add test-integrity@^2.0.1
 
 # ******************************************************************************
 # Now that we used create-react-app to create an app depending on react-scripts,
@@ -186,20 +114,14 @@ npm install test-integrity@^2.0.1
 # Enter the app directory
 cd "$temp_app_path/test-kitchensink"
 
-# Link to our preset
-install_package "$root_path"/packages/babel-preset-react-app
-# Link to error overlay package because now it's a dependency
-# of react-dev-utils and not react-scripts
-install_package "$root_path"/packages/react-error-overlay
-
 # Link to test module
-install_package "$temp_module_path/node_modules/test-integrity"
+npm link "$temp_module_path/node_modules/test-integrity"
 
 # Test the build
 REACT_APP_SHELL_ENV_MESSAGE=fromtheshell \
   NODE_PATH=src \
   PUBLIC_URL=http://www.example.org/spa/ \
-  npm run build
+  yarn build
 
 # Check for expected output
 exists build/*.html
@@ -210,22 +132,15 @@ REACT_APP_SHELL_ENV_MESSAGE=fromtheshell \
   CI=true \
   NODE_PATH=src \
   NODE_ENV=test \
-  npm test -- --no-cache --testPathPattern=src
+  yarn test --no-cache --testPathPattern=src
 
 # Test "development" environment
 tmp_server_log=`mktemp`
 PORT=3001 \
   REACT_APP_SHELL_ENV_MESSAGE=fromtheshell \
   NODE_PATH=src \
-  nohup npm start &>$tmp_server_log &
-while true
-do
-  if grep -q 'You can now view' $tmp_server_log; then
-    break
-  else
-    sleep 1
-  fi
-done
+  nohup yarn start &>$tmp_server_log &
+grep -q 'You can now view' <(tail -f $tmp_server_log)
 E2E_URL="http://localhost:3001" \
   REACT_APP_SHELL_ENV_MESSAGE=fromtheshell \
   CI=true NODE_PATH=src \
@@ -247,28 +162,14 @@ E2E_FILE=./build/index.html \
 # Eject...
 echo yes | npm run eject
 
-# Ensure Yarn is ran after eject; at the time of this commit, we don't run Yarn
-# after ejecting. Soon, we may only skip Yarn on Windows. Let's try to remove
-# this in the near future.
-if hash yarnpkg 2>/dev/null
-then
-  yarn install --check-files
-fi
-
-# ...but still link to the local packages
-install_package "$root_path"/packages/babel-preset-react-app
-install_package "$root_path"/packages/eslint-config-react-app
-install_package "$root_path"/packages/react-error-overlay
-install_package "$root_path"/packages/react-dev-utils
-
 # Link to test module
-install_package "$temp_module_path/node_modules/test-integrity"
+npm link "$temp_module_path/node_modules/test-integrity"
 
 # Test the build
 REACT_APP_SHELL_ENV_MESSAGE=fromtheshell \
   NODE_PATH=src \
   PUBLIC_URL=http://www.example.org/spa/ \
-  npm run build
+  yarn build
 
 # Check for expected output
 exists build/*.html
@@ -279,22 +180,15 @@ REACT_APP_SHELL_ENV_MESSAGE=fromtheshell \
   CI=true \
   NODE_PATH=src \
   NODE_ENV=test \
-  npm test -- --no-cache --testPathPattern=src
+  yarn test --no-cache --testPathPattern=src
 
 # Test "development" environment
 tmp_server_log=`mktemp`
 PORT=3002 \
   REACT_APP_SHELL_ENV_MESSAGE=fromtheshell \
   NODE_PATH=src \
-  nohup npm start &>$tmp_server_log &
-while true
-do
-  if grep -q 'You can now view' $tmp_server_log; then
-    break
-  else
-    sleep 1
-  fi
-done
+  nohup yarn start &>$tmp_server_log &
+grep -q 'You can now view' <(tail -f $tmp_server_log)
 E2E_URL="http://localhost:3002" \
   REACT_APP_SHELL_ENV_MESSAGE=fromtheshell \
   CI=true NODE_PATH=src \
@@ -310,4 +204,4 @@ E2E_FILE=./build/index.html \
   node_modules/.bin/mocha --require babel-register --require babel-polyfill integration/*.test.js
 
 # Cleanup
-cleanup
+cleanup
\ No newline at end of file
diff --git a/tasks/e2e-old-node.sh b/tasks/e2e-old-node.sh
index 8245dd24e..2d0345ba0 100755
--- a/tasks/e2e-old-node.sh
+++ b/tasks/e2e-old-node.sh
@@ -58,4 +58,4 @@ err_output=`node "$root_path"/packages/create-react-app/index.js test-node-versi
 [[ $err_output =~ You\ are\ running\ Node ]] && exit 0 || exit 1
 
 # Cleanup
-cleanup
+cleanup
\ No newline at end of file
diff --git a/tasks/e2e-simple.sh b/tasks/e2e-simple.sh
index 04781ebaf..a1eecbaf0 100755
--- a/tasks/e2e-simple.sh
+++ b/tasks/e2e-simple.sh
@@ -12,17 +12,21 @@
 # Start in tasks/ even if run from root directory
 cd "$(dirname "$0")"
 
-# CLI and app temporary locations
+# App temporary location
 # http://unix.stackexchange.com/a/84980
-temp_cli_path=`mktemp -d 2>/dev/null || mktemp -d -t 'temp_cli_path'`
 temp_app_path=`mktemp -d 2>/dev/null || mktemp -d -t 'temp_app_path'`
+custom_registry_url=http://localhost:4873
+original_npm_registry_url=`npm get registry`
+original_yarn_registry_url=`yarn config get registry`
 
 function cleanup {
   echo 'Cleaning up.'
   cd "$root_path"
   # Uncomment when snapshot testing is enabled by default:
   # rm ./packages/react-scripts/template/src/__snapshots__/App.test.js.snap
-  rm -rf "$temp_cli_path" $temp_app_path
+  rm -rf "$temp_app_path"
+  npm set registry "$original_npm_registry_url"
+  yarn config set registry "$original_yarn_registry_url"
 }
 
 # Error messages are redirected to stderr
@@ -39,35 +43,6 @@ function handle_exit {
   exit
 }
 
-function create_react_app {
-  node "$temp_cli_path"/node_modules/create-react-app/index.js "$@"
-}
-
-function install_package {
-  local pkg=$(basename $1)
-
-  # Clean target (for safety)
-  rm -rf node_modules/$pkg/
-  rm -rf node_modules/**/$pkg/
-
-  # Copy package into node_modules/ ignoring installed deps
-  # rsync -a ${1%/} node_modules/ --exclude node_modules
-  cp -R ${1%/} node_modules/
-  rm -rf node_modules/$pkg/node_modules/
-
-  # Install `dependencies`
-  cd node_modules/$pkg/
-  if [ "$USE_YARN" = "yes" ]
-  then
-    yarn install --production
-  else
-    npm install --only=production
-  fi
-  # Remove our packages to ensure side-by-side versions are used (which we link)
-  rm -rf node_modules/{babel-preset-react-app,eslint-config-react-app,react-dev-utils,react-error-overlay,react-scripts}
-  cd ../..
-}
-
 # Check for the existence of one or more files.
 function exists {
   for f in $*; do
@@ -88,65 +63,40 @@ set -x
 cd ..
 root_path=$PWD
 
-# Clear cache to avoid issues with incorrect packages being used
-if hash yarnpkg 2>/dev/null
-then
-  # AppVeyor uses an old version of yarn.
-  # Once updated to 0.24.3 or above, the workaround can be removed
-  # and replaced with `yarnpkg cache clean`
-  # Issues:
-  #    https://github.com/yarnpkg/yarn/issues/2591
-  #    https://github.com/appveyor/ci/issues/1576
-  #    https://github.com/facebookincubator/create-react-app/pull/2400
-  # When removing workaround, you may run into
-  #    https://github.com/facebookincubator/create-react-app/issues/2030
-  case "$(uname -s)" in
-    *CYGWIN*|MSYS*|MINGW*) yarn=yarn.cmd;;
-    *) yarn=yarnpkg;;
-  esac
-  $yarn cache clean
+# Make sure we don't introduce accidental references to PATENTS.
+EXPECTED='packages/react-error-overlay/fixtures/bundle.mjs
+packages/react-error-overlay/fixtures/bundle.mjs.map
+packages/react-error-overlay/fixtures/bundle_u.mjs
+packages/react-error-overlay/fixtures/bundle_u.mjs.map
+tasks/e2e-simple.sh'
+ACTUAL=$(git grep -l PATENTS)
+if [ "$EXPECTED" != "$ACTUAL" ]; then
+  echo "PATENTS crept into some new files?"
+  diff -u <(echo "$EXPECTED") <(echo "$ACTUAL") || true
+  exit 1
 fi
 
 if hash npm 2>/dev/null
 then
-  # npm 5 is too buggy right now
-  if [ $(npm -v | head -c 1) -eq 5 ]; then
-    npm i -g npm@^4.x
-  fi;
+  npm i -g npm@latest
   npm cache clean || npm cache verify
 fi
 
-# Prevent bootstrap, we only want top-level dependencies
-cp package.json package.json.bak
-grep -v "postinstall" package.json > temp && mv temp package.json
-npm install
-mv package.json.bak package.json
-
-# We need to install create-react-app deps to test it
-cd "$root_path"/packages/create-react-app
-npm install
-cd "$root_path"
-
-# If the node version is < 6, the script should just give an error.
-nodeVersion=`node --version | cut -d v -f2`
-nodeMajor=`echo $nodeVersion | cut -d. -f1`
-nodeMinor=`echo $nodeVersion | cut -d. -f2`
-if [[ nodeMajor -lt 6 ]]
-then
-  cd $temp_app_path
-  err_output=`node "$root_path"/packages/create-react-app/index.js test-node-version 2>&1 > /dev/null || echo ''`
-  [[ $err_output =~ You\ are\ running\ Node ]] && exit 0 || exit 1
-fi
+# Bootstrap monorepo
+yarn
 
-if [ "$USE_YARN" = "yes" ]
-then
-  # Install Yarn so that the test can use it to install packages.
-  npm install -g yarn
-  yarn cache clean
-fi
+# Start local registry
+tmp_registry_log=`mktemp`
+nohup npx verdaccio@2.7.2 &>$tmp_registry_log &
+# Wait for `verdaccio` to boot
+grep -q 'http address' <(tail -f $tmp_registry_log)
 
-# We removed the postinstall, so do it manually here
-node bootstrap.js
+# Set registry to local registry
+npm set registry "$custom_registry_url"
+yarn config set registry "$custom_registry_url"
+
+# Login so we can publish packages
+npx npm-cli-login@0.0.10 -u user -p password -e user@example.com -r "$custom_registry_url" --quotes
 
 # Lint own code
 ./node_modules/.bin/eslint --max-warnings 0 packages/babel-preset-react-app/
@@ -156,8 +106,16 @@ node bootstrap.js
 ./node_modules/.bin/eslint --max-warnings 0 packages/react-scripts/
 cd packages/react-error-overlay/
 ./node_modules/.bin/eslint --max-warnings 0 src/
-npm test
-npm run build:prod
+yarn test
+
+if [ $APPVEYOR != 'True' ]; then
+  # Flow started hanging on AppVeyor after we moved to Yarn Workspaces :-(
+  yarn flow
+fi
+
+cd ../..
+cd packages/react-dev-utils/
+yarn test
 cd ../..
 
 # ******************************************************************************
@@ -166,7 +124,7 @@ cd ../..
 # ******************************************************************************
 
 # Test local build command
-npm run build
+yarn build
 # Check for expected output
 exists build/*.html
 exists build/static/js/*.js
@@ -175,55 +133,25 @@ exists build/static/media/*.svg
 exists build/favicon.ico
 
 # Run tests with CI flag
-CI=true npm test
+CI=true yarn test
 # Uncomment when snapshot testing is enabled by default:
 # exists template/src/__snapshots__/App.test.js.snap
 
 # Test local start command
-npm start -- --smoke-test
-
-# ******************************************************************************
-# Next, pack react-scripts and create-react-app so we can verify they work.
-# ******************************************************************************
-
-# Pack CLI
-cd "$root_path"/packages/create-react-app
-cli_path=$PWD/`npm pack`
-
-# Go to react-scripts
-cd "$root_path"/packages/react-scripts
+yarn start --smoke-test
 
-# Save package.json because we're going to touch it
-cp package.json package.json.orig
-
-# Replace own dependencies (those in the `packages` dir) with the local paths
-# of those packages.
-node "$root_path"/tasks/replace-own-deps.js
-
-# Finally, pack react-scripts
-scripts_path="$root_path"/packages/react-scripts/`npm pack`
-
-# Restore package.json
-rm package.json
-mv package.json.orig package.json
+git clean -df
+./tasks/publish.sh --yes --force-publish=* --skip-git --cd-version=prerelease --exact --npm-tag=latest
 
 # ******************************************************************************
-# Now that we have packed them, create a clean app folder and install them.
+# Install react-scripts prerelease via create-react-app prerelease.
 # ******************************************************************************
 
-# Install the CLI in a temporary location
-cd "$temp_cli_path"
-
-# Initialize package.json before installing the CLI because npm will not install
-# the CLI properly in the temporary location if it is missing.
-npm init --yes
-
-# Now we can install the CLI from the local package.
-npm install "$cli_path"
-
 # Install the app in a temporary location
 cd $temp_app_path
-create_react_app --scripts-version="$scripts_path" test-app
+npx create-react-app test-app --scripts-version=react-scripts-ts
+
+# TODO: verify we installed prerelease
 
 # ******************************************************************************
 # Now that we used create-react-app to create an app depending on react-scripts,
@@ -240,24 +168,24 @@ function verify_env_url {
   # Test relative path build
   awk -v n=2 -v s="  \"homepage\": \".\"," 'NR == n {print s} {print}' package.json > tmp && mv tmp package.json
 
-  npm run build
+  yarn build
   # Disabled until this can be tested
   # grep -F -R --exclude=*.map "../../static/" build/ -q; test $? -eq 0 || exit 1
   grep -F -R --exclude=*.map "\"./static/" build/ -q; test $? -eq 0 || exit 1
   grep -F -R --exclude=*.map "\"/static/" build/ -q; test $? -eq 1 || exit 1
 
-  PUBLIC_URL="/anabsolute" npm run build
+  PUBLIC_URL="/anabsolute" yarn build
   grep -F -R --exclude=*.map "/anabsolute/static/" build/ -q; test $? -eq 0 || exit 1
   grep -F -R --exclude=*.map "\"/static/" build/ -q; test $? -eq 1 || exit 1
 
   # Test absolute path build
   sed "2s/.*/  \"homepage\": \"\/testingpath\",/" package.json > tmp && mv tmp package.json
 
-  npm run build
+  yarn build
   grep -F -R --exclude=*.map "/testingpath/static/" build/ -q; test $? -eq 0 || exit 1
   grep -F -R --exclude=*.map "\"/static/" build/ -q; test $? -eq 1 || exit 1
 
-  PUBLIC_URL="https://www.example.net/overridetest" npm run build
+  PUBLIC_URL="https://www.example.net/overridetest" yarn build
   grep -F -R --exclude=*.map "https://www.example.net/overridetest/static/" build/ -q; test $? -eq 0 || exit 1
   grep -F -R --exclude=*.map "\"/static/" build/ -q; test $? -eq 1 || exit 1
   grep -F -R --exclude=*.map "testingpath/static" build/ -q; test $? -eq 1 || exit 1
@@ -265,11 +193,11 @@ function verify_env_url {
   # Test absolute url build
   sed "2s/.*/  \"homepage\": \"https:\/\/www.example.net\/testingpath\",/" package.json > tmp && mv tmp package.json
 
-  npm run build
+  yarn build
   grep -F -R --exclude=*.map "/testingpath/static/" build/ -q; test $? -eq 0 || exit 1
   grep -F -R --exclude=*.map "\"/static/" build/ -q; test $? -eq 1 || exit 1
 
-  PUBLIC_URL="https://www.example.net/overridetest" npm run build
+  PUBLIC_URL="https://www.example.net/overridetest" yarn build
   grep -F -R --exclude=*.map "https://www.example.net/overridetest/static/" build/ -q; test $? -eq 0 || exit 1
   grep -F -R --exclude=*.map "\"/static/" build/ -q; test $? -eq 1 || exit 1
   grep -F -R --exclude=*.map "testingpath/static" build/ -q; test $? -eq 1 || exit 1
@@ -283,14 +211,14 @@ function verify_module_scope {
   # Create stub json file
   echo "{}" >> sample.json
 
-  # Save App.js, we're going to modify it
+  # Save App.tsx, we're going to modify it
   cp src/App.tsx src/App.tsx.bak
 
   # Add an out of scope import
-  echo "import sampleJson from '../sample.json'" | cat - src/App.tsx > src/App.tsx.temp && mv src/App.tsx.temp src/App.tsx
+  echo "import sampleJson from '../sample'" | cat - src/App.tsx > src/App.tsx.temp && mv src/App.tsx.temp src/App.tsx
 
   # Make sure the build fails
-  npm run build; test $? -eq 1 || exit 1
+  yarn build; test $? -eq 1 || exit 1
   # TODO: check for error message
 
   # Restore App.tsx
@@ -302,9 +230,8 @@ function verify_module_scope {
 cd test-app
 
 # Test the build
-npm run build
+yarn build
 # Check for expected output
-pwd
 exists build/*.html
 exists build/static/js/*.js
 exists build/static/css/*.css
@@ -312,12 +239,12 @@ exists build/static/media/*.svg
 exists build/favicon.ico
 
 # Run tests with CI flag
-CI=true npm test
+CI=true yarn test
 # Uncomment when snapshot testing is enabled by default:
-# exists src/__snapshots__/App.test.tsx.snap
+# exists src/__snapshots__/App.test.js.snap
 
 # Test the server
-npm start -- --smoke-test
+yarn start --smoke-test
 
 # Test environment handling
 verify_env_url
@@ -332,21 +259,8 @@ verify_module_scope
 # Eject...
 echo yes | npm run eject
 
-# Ensure Yarn is ran after eject; at the time of this commit, we don't run Yarn
-# after ejecting. Soon, we may only skip Yarn on Windows. Let's try to remove
-# this in the near future.
-if hash yarnpkg 2>/dev/null
-then
-  yarnpkg install --check-files
-fi
-
-# ...but still link to the local packages
-install_package "$root_path"/packages/babel-preset-react-app
-install_package "$root_path"/packages/eslint-config-react-app
-install_package "$root_path"/packages/react-dev-utils
-
 # Test the build
-npm run build
+yarn build
 # Check for expected output
 exists build/*.html
 exists build/static/js/*.js
@@ -355,15 +269,15 @@ exists build/static/media/*.svg
 exists build/favicon.ico
 
 # Run tests, overring the watch option to disable it.
-# `CI=true npm test` won't work here because `npm test` becomes just `jest`.
+# `CI=true yarn test` won't work here because `yarn test` becomes just `jest`.
 # We should either teach Jest to respect CI env variable, or make
 # `scripts/test.js` survive ejection (right now it doesn't).
-npm test -- --watch=no
+yarn test --watch=no
 # Uncomment when snapshot testing is enabled by default:
 # exists src/__snapshots__/App.test.js.snap
 
 # Test the server
-npm start -- --smoke-test
+yarn start --smoke-test
 
 # Test environment handling
 verify_env_url
@@ -372,4 +286,4 @@ verify_env_url
 verify_module_scope
 
 # Cleanup
-cleanup
+cleanup
\ No newline at end of file
diff --git a/tasks/local-test.sh b/tasks/local-test.sh
index 8ce44b640..1cab41f67 100755
--- a/tasks/local-test.sh
+++ b/tasks/local-test.sh
@@ -11,7 +11,6 @@ function print_help {
   echo "  --node-version <version>  the node version to use while testing [6]"
   echo "  --git-branch <branch>     the git branch to checkout for testing [the current one]"
   echo "  --test-suite <suite>      which test suite to use ('simple', installs', 'kitchensink', 'all') ['all']"
-  echo "  --yarn                    if present, use yarn as the package manager"
   echo "  --interactive             gain a bash shell after the test run"
   echo "  --help                    print this message and exit"
   echo ""
@@ -22,7 +21,6 @@ cd $(dirname $0)
 node_version=6
 current_git_branch=`git rev-parse --abbrev-ref HEAD`
 git_branch=${current_git_branch}
-use_yarn=no
 test_suite=all
 interactive=false
 
@@ -36,9 +34,6 @@ while [ "$1" != "" ]; do
       shift
       git_branch=$1
       ;;
-    "--yarn")
-      use_yarn=yes
-      ;;
     "--test-suite")
       shift
       test_suite=$1
@@ -107,11 +102,10 @@ CMD
 docker run \
   --env CI=true \
   --env NPM_CONFIG_QUIET=true \
-  --env USE_YARN=${use_yarn} \
   --tty \
   --user node \
   --volume ${PWD}/..:/var/create-react-app \
   --workdir /home/node \
   $([[ ${interactive} == 'true' ]] && echo '--interactive') \
   node:${node_version} \
-  bash -c "${command}"
+  bash -c "${command}"
\ No newline at end of file