diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
index ac8f5df79..0cf6c89ac 100644
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -128,7 +128,7 @@ $ node /projects/theia/production/src-gen/backend/main.js /tmp/theiadev_projects
 You can then access to your modified Che-theia from the Container view `theia-dev` endpoint
 ![Che-Theia-dev-endpoint](https://raw.githubusercontent.com/eclipse/che-theia/assets/theia-dev-endpoint.png)
 
-### Step 7bis: Run che-theia + plugin in dev mode
+### Step 7: Run che-theia + plugin in dev mode
 In this section we show how to run the che-theia assembly but in `dev mode`: keeping all the information for debugging.
 
 You can use the che command `run ... DEV yarn start ... che-theia + factory-plugin` or
@@ -144,6 +144,9 @@ If you do not have any changes on Theia or Che-theia extension, you could just b
 and run these plugins with the existing che-theia app:
 `run ... HOSTED che-theia + container-plugin` or `run ... HOSTED che-theia + factory-plugin`
 
+### How to run Che Theia with VS Code builtin extensions
+
+First of all it is needed to download extensions: `download builtin extensions ... DEV che-theia`. Then start che-theia: `run ... HOSTED che-theia + builtin extensions`.
 
 ## How to develop Che Theia remote plugin mechanism
 
@@ -161,7 +164,7 @@ When workspace is ready:
    Or a user may generate one using `Generate Hello World plugin package` command.
  - Run dev Che Theia and Remote plugins endpoint in `theia-dev` and `theia-remote-runtime-dev` containers correspondingly.
    One may use predefined commands to start them.
- - Open `theia-dev` route from `My Workspace` panel and test chenges.
+ - Open `theia-dev` route from `My Workspace` panel and test changes.
 
 Also it is possible to run watchers for remote plugin mechanism.
 In `theia-dev` container run `npx run watch @eclipse-che/theia-remote` from `/projects/theia` folder to recompile the extension on changes made.
diff --git a/devfiles/che-theia-all.devfile.yaml b/devfiles/che-theia-all.devfile.yaml
index f3711a411..5419d5c2d 100644
--- a/devfiles/che-theia-all.devfile.yaml
+++ b/devfiles/che-theia-all.devfile.yaml
@@ -59,6 +59,15 @@ commands:
                  echo -e "\e[32mDone.\e[0m che:theia init"
         workdir: /projects/theia
 
+  - name: download builtin extensions ... DEV che-theia
+    actions:
+      - type: exec
+        component: che-dev
+        command: >
+                 che:theia builtin-extensions --plugins builtin-extensions &&
+                 echo -e "\e[32mDone.\e[0m che:theia extensions"
+        workdir: /projects
+
   - name: clean ... DEV che-theia
     actions:
       - type: exec
@@ -134,6 +143,17 @@ commands:
                  node src-gen/backend/main.js /tmp/theiadev_projects --hostname=0.0.0.0 --port=3130 & echo $!> /tmp/node_theiadev.pid ; wait `cat /tmp/node_theiadev.pid`
         workdir: /projects/theia/production
 
+  - name: run ... DEV che-theia + builtin extensions
+    actions:
+      - type: exec
+        component: theia-editor
+        command: >
+                 kill `cat /tmp/node_theiadev.pid`;
+                 mkdir -p /tmp/theiadev_projects &&
+                 export CHE_PROJECTS_ROOT=/tmp/theiadev_projects &&
+                 node src-gen/backend/main.js /tmp/theiadev_projects --hostname=0.0.0.0 --port=3130 --plugins=local-dir:/projects/builtin-extensions & echo $!> /tmp/node_theiadev.pid ; wait `cat /tmp/node_theiadev.pid`
+        workdir: /projects/theia/production
+
   - name: run ... HOSTED che-theia + factory-plugin
     actions:
       - type: exec
@@ -160,6 +180,17 @@ commands:
                  node src-gen/backend/main.js /tmp/theiadev_projects --hostname=0.0.0.0 --port=3130 & echo $!> /tmp/node_theiadev.pid ; wait `cat /tmp/node_theiadev.pid`
         workdir: /home/theia
 
+  - name: run ... HOSTED che-theia + builtin extensions
+    actions:
+      - type: exec
+        component: theia-editor
+        command: >
+                 kill `cat /tmp/node_theiadev.pid`;
+                 mkdir -p /tmp/theiadev_projects &&
+                 export CHE_PROJECTS_ROOT=/tmp/theiadev_projects &&
+                 node src-gen/backend/main.js /tmp/theiadev_projects --hostname=0.0.0.0 --port=3130 --plugins=local-dir:/projects/builtin-extensions & echo $!> /tmp/node_theiadev.pid ; wait `cat /tmp/node_theiadev.pid`
+        workdir: /home/theia
+
   - name: run ... DEV yarn start ... che-theia + factory-plugin
     actions:
       - type: exec
diff --git a/dockerfiles/theia/Dockerfile b/dockerfiles/theia/Dockerfile
index 0fb06f52a..a719d9430 100644
--- a/dockerfiles/theia/Dockerfile
+++ b/dockerfiles/theia/Dockerfile
@@ -79,6 +79,9 @@ RUN if [ -z $GITHUB_TOKEN ]; then unset GITHUB_TOKEN; fi && \
 #{INCLUDE:docker/${BUILD_IMAGE_TARGET}/builder-before-production.dockerfile}
 RUN che:theia production
 
+# run che:theia builtin-extensions to download vscode builtin extensions
+RUN che:theia builtin-extensions --plugins builtin-extensions
+
 # Compile plugins
 RUN if [ -z $GITHUB_TOKEN ]; then unset GITHUB_TOKEN; fi && \
     cd plugins && ./foreach_yarn
@@ -115,13 +118,13 @@ ENV USE_LOCAL_GIT=true \
 EXPOSE 3100 3130
 
 COPY --from=builder /home/theia-dev/theia-source-code/production/plugins /default-theia-plugins
-
+COPY --from=builder /home/theia-dev/theia-source-code/builtin-extensions /default-theia-plugins
 #{INCLUDE:docker/${BUILD_IMAGE_TARGET}/runtime-install-dependencies.dockerfile}
 
 # setup yarn (if missing)
 #{INCLUDE:docker/${BUILD_IMAGE_TARGET}/runtime-setup-yarn.dockerfile}
 
- RUN \
+RUN \
     #{INCLUDE:docker/${BUILD_IMAGE_TARGET}/runtime-adduser.sh}
     && echo "%wheel ALL=(ALL) NOPASSWD: ALL" >> /etc/sudoers \
     # Create /projects for Che
diff --git a/generator/src/__mocks__/command.ts b/generator/src/__mocks__/command.ts
index 8b6a7e22f..fe7475c18 100644
--- a/generator/src/__mocks__/command.ts
+++ b/generator/src/__mocks__/command.ts
@@ -19,10 +19,15 @@ export class Command {
      * Map between the name of the exec command and the output.
      */
     private static readonly execMap: Map<string, string> = new Map();
+    private static readonly execRegExpMap: Map<RegExp, string> = new Map();
 
     // mock any exec command by providing the output
-    public static __setExecCommandOutput(command: string, output: string): void {
-        Command.execMap.set(command, output);
+    public static __setExecCommandOutput(command: string | RegExp, output: string): void {
+        if (typeof command === 'string') {
+            Command.execMap.set(command, output);
+        } else {
+            Command.execRegExpMap.set(command, output);
+        }
     }
 
     constructor() {
@@ -34,6 +39,11 @@ export class Command {
         if (result) {
             return Promise.resolve(result);
         } else {
+            for (const entry of Command.execRegExpMap) {
+                if (entry[0].test(command)) {
+                    return entry[1];
+                }
+            }
             return Promise.resolve('');
         }
     }
diff --git a/generator/src/builtin-extensions.ts b/generator/src/builtin-extensions.ts
new file mode 100644
index 000000000..24051e3cf
--- /dev/null
+++ b/generator/src/builtin-extensions.ts
@@ -0,0 +1,69 @@
+/*********************************************************************
+* Copyright (c) 2019 Red Hat, Inc.
+*
+* This program and the accompanying materials are made
+* available under the terms of the Eclipse Public License 2.0
+* which is available at https://www.eclipse.org/legal/epl-2.0/
+*
+* SPDX-License-Identifier: EPL-2.0
+**********************************************************************/
+import * as axios from 'axios';
+import * as fs from 'fs-extra';
+import * as path from 'path';
+import * as yargs from 'yargs';
+import { Logger } from './logger';
+
+/**
+ * Downloads builtin extensions.
+ * @author Anatolii Bazko
+ */
+export class BuiltinExtensions {
+    static argBuilder = (theYargs: yargs.Argv) => {
+        return theYargs.option('plugins', {
+            description: 'Plugins folder to download VS Code builtin extension into.',
+            alias: 'p',
+        }).option('extensions', {
+            description: 'List of VS Code builtin extensions to download.',
+            alias: 'e',
+        });
+    }
+
+    constructor(
+        protected readonly pluginsFolder: string, protected readonly extensions?: string) {
+    }
+
+    async download(): Promise<string[]> {
+        const downloaded = [];
+
+        await fs.ensureDir(this.pluginsFolder);
+        const srcDir = path.resolve(__dirname, '../src');
+        const confDir = path.join(srcDir, 'conf');
+        const extensions = this.extensions || await fs.readFile(path.join(confDir, 'builtin-extensions'));
+
+        Logger.info(`Downloading extensions into '${this.pluginsFolder}' started`);
+
+        for (const extension of extensions.toString().split('\n')) {
+            if (!extension.trim() || extension.startsWith('//')) {
+                continue;
+            }
+
+            Logger.info(`Downloading '${extension}'`);
+            try {
+                await this.downloadExtension(extension);
+                downloaded.push(extension);
+            } catch (error) {
+                Logger.error(error);
+            }
+        }
+
+        Logger.info('Downloading extensions completed.');
+        return downloaded;
+    }
+
+    protected async downloadExtension(extension: string): Promise<void> {
+        const response = await axios.default.get(extension);
+        const filename = extension.substring(extension.lastIndexOf('/') + 1);
+
+        fs.writeFileSync(path.resolve(this.pluginsFolder, filename), response.data);
+    }
+}
diff --git a/generator/src/conf/builtin-extensions b/generator/src/conf/builtin-extensions
new file mode 100644
index 000000000..d7ef9435a
--- /dev/null
+++ b/generator/src/conf/builtin-extensions
@@ -0,0 +1,47 @@
+https://github.com/theia-ide/vscode-builtin-extensions/releases/download/v1.39.1-prel/bat-1.39.1-prel.vsix
+https://github.com/theia-ide/vscode-builtin-extensions/releases/download/v1.39.1-prel/clojure-1.39.1-prel.vsix
+https://github.com/theia-ide/vscode-builtin-extensions/releases/download/v1.39.1-prel/coffeescript-1.39.1-prel.vsix
+https://github.com/theia-ide/vscode-builtin-extensions/releases/download/v1.39.1-prel/configuration-editing-1.39.1-prel.vsix
+https://github.com/theia-ide/vscode-builtin-extensions/releases/download/v1.39.1-prel/cpp-1.39.1-prel.vsix
+https://github.com/theia-ide/vscode-builtin-extensions/releases/download/v1.39.1-prel/csharp-1.39.1-prel.vsix
+https://github.com/theia-ide/vscode-builtin-extensions/releases/download/v1.39.1-prel/css-1.39.1-prel.vsix
+https://github.com/theia-ide/vscode-builtin-extensions/releases/download/v1.39.1-prel/debug-auto-launch-1.39.1-prel.vsix
+https://github.com/theia-ide/vscode-builtin-extensions/releases/download/v1.39.1-prel/docker-1.39.1-prel.vsix
+https://github.com/theia-ide/vscode-builtin-extensions/releases/download/v1.39.1-prel/fsharp-1.39.1-prel.vsix
+https://github.com/theia-ide/vscode-builtin-extensions/releases/download/v1.39.1-prel/go-1.39.1-prel.vsix
+https://github.com/theia-ide/vscode-builtin-extensions/releases/download/v1.39.1-prel/groovy-1.39.1-prel.vsix
+https://github.com/theia-ide/vscode-builtin-extensions/releases/download/v1.39.1-prel/grunt-1.39.1-prel.vsix
+https://github.com/theia-ide/vscode-builtin-extensions/releases/download/v1.39.1-prel/gulp-1.39.1-prel.vsix
+https://github.com/theia-ide/vscode-builtin-extensions/releases/download/v1.39.1-prel/handlebars-1.39.1-prel.vsix
+https://github.com/theia-ide/vscode-builtin-extensions/releases/download/v1.39.1-prel/hlsl-1.39.1-prel.vsix
+https://github.com/theia-ide/vscode-builtin-extensions/releases/download/v1.39.1-prel/html-1.39.1-prel.vsix
+https://github.com/theia-ide/vscode-builtin-extensions/releases/download/v1.39.1-prel/ini-1.39.1-prel.vsix
+https://github.com/theia-ide/vscode-builtin-extensions/releases/download/v1.39.1-prel/jake-1.39.1-prel.vsix
+https://github.com/theia-ide/vscode-builtin-extensions/releases/download/v1.39.1-prel/java-1.39.1-prel.vsix
+https://github.com/theia-ide/vscode-builtin-extensions/releases/download/v1.39.1-prel/javascript-1.39.1-prel.vsix
+https://github.com/theia-ide/vscode-builtin-extensions/releases/download/v1.39.1-prel/json-1.39.1-prel.vsix
+https://github.com/theia-ide/vscode-builtin-extensions/releases/download/v1.39.1-prel/less-1.39.1-prel.vsix
+https://github.com/theia-ide/vscode-builtin-extensions/releases/download/v1.39.1-prel/log-1.39.1-prel.vsix
+https://github.com/theia-ide/vscode-builtin-extensions/releases/download/v1.39.1-prel/lua-1.39.1-prel.vsix
+https://github.com/theia-ide/vscode-builtin-extensions/releases/download/v1.39.1-prel/make-1.39.1-prel.vsix
+https://github.com/theia-ide/vscode-builtin-extensions/releases/download/v1.39.1-prel/markdown-1.39.1-prel.vsix
+https://github.com/theia-ide/vscode-builtin-extensions/releases/download/v1.39.1-prel/merge-conflict-1.39.1-prel.vsix
+https://github.com/theia-ide/vscode-builtin-extensions/releases/download/v1.39.1-prel/npm-1.39.1-prel.vsix
+https://github.com/theia-ide/vscode-builtin-extensions/releases/download/v1.39.1-prel/objective-c-1.39.1-prel.vsix
+https://github.com/theia-ide/vscode-builtin-extensions/releases/download/v1.39.1-prel/perl-1.39.1-prel.vsix
+https://github.com/theia-ide/vscode-builtin-extensions/releases/download/v1.39.1-prel/powershell-1.39.1-prel.vsix
+https://github.com/theia-ide/vscode-builtin-extensions/releases/download/v1.39.1-prel/pug-1.39.1-prel.vsix
+https://github.com/theia-ide/vscode-builtin-extensions/releases/download/v1.39.1-prel/python-1.39.1-prel.vsix
+https://github.com/theia-ide/vscode-builtin-extensions/releases/download/v1.39.1-prel/r-1.39.1-prel.vsix
+https://github.com/theia-ide/vscode-builtin-extensions/releases/download/v1.39.1-prel/razor-1.39.1-prel.vsix
+https://github.com/theia-ide/vscode-builtin-extensions/releases/download/v1.39.1-prel/ruby-1.39.1-prel.vsix
+https://github.com/theia-ide/vscode-builtin-extensions/releases/download/v1.39.1-prel/rust-1.39.1-prel.vsix
+https://github.com/theia-ide/vscode-builtin-extensions/releases/download/v1.39.1-prel/scss-1.39.1-prel.vsix
+https://github.com/theia-ide/vscode-builtin-extensions/releases/download/v1.39.1-prel/shaderlab-1.39.1-prel.vsix
+https://github.com/theia-ide/vscode-builtin-extensions/releases/download/v1.39.1-prel/shellscript-1.39.1-prel.vsix
+https://github.com/theia-ide/vscode-builtin-extensions/releases/download/v1.39.1-prel/sql-1.39.1-prel.vsix
+https://github.com/theia-ide/vscode-builtin-extensions/releases/download/v1.39.1-prel/swift-1.39.1-prel.vsix
+https://github.com/theia-ide/vscode-builtin-extensions/releases/download/v1.39.1-prel/typescript-1.39.1-prel.vsix
+https://github.com/theia-ide/vscode-builtin-extensions/releases/download/v1.39.1-prel/vb-1.39.1-prel.vsix
+https://github.com/theia-ide/vscode-builtin-extensions/releases/download/v1.39.1-prel/xml-1.39.1-prel.vsix
+https://github.com/theia-ide/vscode-builtin-extensions/releases/download/v1.39.1-prel/yaml-1.39.1-prel.vsix
diff --git a/generator/src/templates/assembly-package.mst b/generator/src/templates/assembly-package.mst
index e984fcfa2..c0f819446 100644
--- a/generator/src/templates/assembly-package.mst
+++ b/generator/src/templates/assembly-package.mst
@@ -26,7 +26,6 @@
     "@theia/keymaps": "^{{ version }}",
     "@theia/languages": "^{{ version }}",
     "@theia/markers": "^{{ version }}",
-    "@theia/merge-conflicts": "^{{ version }}",
     "@theia/messages": "^{{ version }}",
     "@theia/metrics": "^{{ version }}",
     "@theia/mini-browser": "^{{ version }}",
@@ -38,11 +37,9 @@
     "@theia/plugin-ext": "^{{ version }}",
     "@theia/plugin-ext-vscode": "^{{ version }}",
     "@theia/preferences": "^{{ version }}",
-    "@theia/preview": "^{{ version }}",
     "@theia/process": "^{{ version }}",
     "@theia/search-in-workspace": "^{{ version }}",
     "@theia/task": "^{{ version }}",
-    "@theia/textmate-grammars": "^{{ version }}",
     "@theia/tslint": "^{{ version }}",
     "@theia/userstorage": "^{{ version }}",
     "@theia/variable-resolver": "^{{ version }}",
diff --git a/generator/src/yargs.ts b/generator/src/yargs.ts
index f8f2af21a..ee830371c 100644
--- a/generator/src/yargs.ts
+++ b/generator/src/yargs.ts
@@ -8,15 +8,16 @@
 * SPDX-License-Identifier: EPL-2.0
 **********************************************************************/
 
-import * as yargs from 'yargs';
-import { Logger } from './logger';
 import * as path from 'path';
+import * as yargs from 'yargs';
+import { BuiltinExtensions } from './builtin-extensions';
+import { Cdn } from './cdn';
+import { Clean } from './clean';
 import { CliError } from './cli-error';
-import { Production } from './production';
 import { Init } from './init';
-import { Cdn } from './cdn';
 import { InitSources } from './init-sources';
-import { Clean } from './clean';
+import { Logger } from './logger';
+import { Production } from './production';
 
 const ASSSEMBLY_PATH = 'examples/assembly';
 
@@ -28,7 +29,7 @@ const commandArgs = yargs
     .usage('$0 <cmd> [args]')
     .command({
         command: 'init',
-        describe: 'Initialize current theia to beahve like a Che/Theia',
+        describe: 'Initialize current theia to behave like a Che/Theia',
         builder: InitSources.argBuilder,
         handler: async (args) => {
             try {
@@ -91,6 +92,20 @@ const commandArgs = yargs
             }
         }
     })
+    .command({
+        command: 'builtin-extensions',
+        describe: 'Download builtin extensions',
+        builder: BuiltinExtensions.argBuilder,
+        handler: async (args) => {
+            try {
+                const pluginsFolder = args.plugins ? path.resolve(args.plugins) : path.resolve(process.cwd(), 'plugins');
+                const builtinExtensions = new BuiltinExtensions(pluginsFolder, args.extensions);
+                await builtinExtensions.download();
+            } catch (err) {
+                handleError(err);
+            }
+        }
+    })
     .help()
     .strict()
     .demandCommand()
diff --git a/generator/tests/builtin-extensions/builtin-extensions b/generator/tests/builtin-extensions/builtin-extensions
new file mode 100644
index 000000000..d7ef9435a
--- /dev/null
+++ b/generator/tests/builtin-extensions/builtin-extensions
@@ -0,0 +1,47 @@
+https://github.com/theia-ide/vscode-builtin-extensions/releases/download/v1.39.1-prel/bat-1.39.1-prel.vsix
+https://github.com/theia-ide/vscode-builtin-extensions/releases/download/v1.39.1-prel/clojure-1.39.1-prel.vsix
+https://github.com/theia-ide/vscode-builtin-extensions/releases/download/v1.39.1-prel/coffeescript-1.39.1-prel.vsix
+https://github.com/theia-ide/vscode-builtin-extensions/releases/download/v1.39.1-prel/configuration-editing-1.39.1-prel.vsix
+https://github.com/theia-ide/vscode-builtin-extensions/releases/download/v1.39.1-prel/cpp-1.39.1-prel.vsix
+https://github.com/theia-ide/vscode-builtin-extensions/releases/download/v1.39.1-prel/csharp-1.39.1-prel.vsix
+https://github.com/theia-ide/vscode-builtin-extensions/releases/download/v1.39.1-prel/css-1.39.1-prel.vsix
+https://github.com/theia-ide/vscode-builtin-extensions/releases/download/v1.39.1-prel/debug-auto-launch-1.39.1-prel.vsix
+https://github.com/theia-ide/vscode-builtin-extensions/releases/download/v1.39.1-prel/docker-1.39.1-prel.vsix
+https://github.com/theia-ide/vscode-builtin-extensions/releases/download/v1.39.1-prel/fsharp-1.39.1-prel.vsix
+https://github.com/theia-ide/vscode-builtin-extensions/releases/download/v1.39.1-prel/go-1.39.1-prel.vsix
+https://github.com/theia-ide/vscode-builtin-extensions/releases/download/v1.39.1-prel/groovy-1.39.1-prel.vsix
+https://github.com/theia-ide/vscode-builtin-extensions/releases/download/v1.39.1-prel/grunt-1.39.1-prel.vsix
+https://github.com/theia-ide/vscode-builtin-extensions/releases/download/v1.39.1-prel/gulp-1.39.1-prel.vsix
+https://github.com/theia-ide/vscode-builtin-extensions/releases/download/v1.39.1-prel/handlebars-1.39.1-prel.vsix
+https://github.com/theia-ide/vscode-builtin-extensions/releases/download/v1.39.1-prel/hlsl-1.39.1-prel.vsix
+https://github.com/theia-ide/vscode-builtin-extensions/releases/download/v1.39.1-prel/html-1.39.1-prel.vsix
+https://github.com/theia-ide/vscode-builtin-extensions/releases/download/v1.39.1-prel/ini-1.39.1-prel.vsix
+https://github.com/theia-ide/vscode-builtin-extensions/releases/download/v1.39.1-prel/jake-1.39.1-prel.vsix
+https://github.com/theia-ide/vscode-builtin-extensions/releases/download/v1.39.1-prel/java-1.39.1-prel.vsix
+https://github.com/theia-ide/vscode-builtin-extensions/releases/download/v1.39.1-prel/javascript-1.39.1-prel.vsix
+https://github.com/theia-ide/vscode-builtin-extensions/releases/download/v1.39.1-prel/json-1.39.1-prel.vsix
+https://github.com/theia-ide/vscode-builtin-extensions/releases/download/v1.39.1-prel/less-1.39.1-prel.vsix
+https://github.com/theia-ide/vscode-builtin-extensions/releases/download/v1.39.1-prel/log-1.39.1-prel.vsix
+https://github.com/theia-ide/vscode-builtin-extensions/releases/download/v1.39.1-prel/lua-1.39.1-prel.vsix
+https://github.com/theia-ide/vscode-builtin-extensions/releases/download/v1.39.1-prel/make-1.39.1-prel.vsix
+https://github.com/theia-ide/vscode-builtin-extensions/releases/download/v1.39.1-prel/markdown-1.39.1-prel.vsix
+https://github.com/theia-ide/vscode-builtin-extensions/releases/download/v1.39.1-prel/merge-conflict-1.39.1-prel.vsix
+https://github.com/theia-ide/vscode-builtin-extensions/releases/download/v1.39.1-prel/npm-1.39.1-prel.vsix
+https://github.com/theia-ide/vscode-builtin-extensions/releases/download/v1.39.1-prel/objective-c-1.39.1-prel.vsix
+https://github.com/theia-ide/vscode-builtin-extensions/releases/download/v1.39.1-prel/perl-1.39.1-prel.vsix
+https://github.com/theia-ide/vscode-builtin-extensions/releases/download/v1.39.1-prel/powershell-1.39.1-prel.vsix
+https://github.com/theia-ide/vscode-builtin-extensions/releases/download/v1.39.1-prel/pug-1.39.1-prel.vsix
+https://github.com/theia-ide/vscode-builtin-extensions/releases/download/v1.39.1-prel/python-1.39.1-prel.vsix
+https://github.com/theia-ide/vscode-builtin-extensions/releases/download/v1.39.1-prel/r-1.39.1-prel.vsix
+https://github.com/theia-ide/vscode-builtin-extensions/releases/download/v1.39.1-prel/razor-1.39.1-prel.vsix
+https://github.com/theia-ide/vscode-builtin-extensions/releases/download/v1.39.1-prel/ruby-1.39.1-prel.vsix
+https://github.com/theia-ide/vscode-builtin-extensions/releases/download/v1.39.1-prel/rust-1.39.1-prel.vsix
+https://github.com/theia-ide/vscode-builtin-extensions/releases/download/v1.39.1-prel/scss-1.39.1-prel.vsix
+https://github.com/theia-ide/vscode-builtin-extensions/releases/download/v1.39.1-prel/shaderlab-1.39.1-prel.vsix
+https://github.com/theia-ide/vscode-builtin-extensions/releases/download/v1.39.1-prel/shellscript-1.39.1-prel.vsix
+https://github.com/theia-ide/vscode-builtin-extensions/releases/download/v1.39.1-prel/sql-1.39.1-prel.vsix
+https://github.com/theia-ide/vscode-builtin-extensions/releases/download/v1.39.1-prel/swift-1.39.1-prel.vsix
+https://github.com/theia-ide/vscode-builtin-extensions/releases/download/v1.39.1-prel/typescript-1.39.1-prel.vsix
+https://github.com/theia-ide/vscode-builtin-extensions/releases/download/v1.39.1-prel/vb-1.39.1-prel.vsix
+https://github.com/theia-ide/vscode-builtin-extensions/releases/download/v1.39.1-prel/xml-1.39.1-prel.vsix
+https://github.com/theia-ide/vscode-builtin-extensions/releases/download/v1.39.1-prel/yaml-1.39.1-prel.vsix
diff --git a/generator/tests/builtin-extensions/builtin-extensions.spec.ts b/generator/tests/builtin-extensions/builtin-extensions.spec.ts
new file mode 100644
index 000000000..6256ae814
--- /dev/null
+++ b/generator/tests/builtin-extensions/builtin-extensions.spec.ts
@@ -0,0 +1,41 @@
+/*********************************************************************
+* Copyright (c) 2019 Red Hat, Inc.
+*
+* This program and the accompanying materials are made
+* available under the terms of the Eclipse Public License 2.0
+* which is available at https://www.eclipse.org/legal/epl-2.0/
+*
+* SPDX-License-Identifier: EPL-2.0
+**********************************************************************/
+
+import * as fs from 'fs-extra';
+import * as path from 'path';
+import * as tmp from 'tmp';
+import { BuiltinExtensions } from '../../src/builtin-extensions';
+
+describe('Test Builtin Extensions', () => {
+
+    let rootFolderTmp: string;
+    let pluginsFolderTmp: string;
+
+    beforeEach(async () => {
+        rootFolderTmp = tmp.dirSync({ mode: 0o750, prefix: 'tmpInit', postfix: '' }).name;
+        pluginsFolderTmp = path.resolve(rootFolderTmp, 'plugins');
+    });
+
+    afterEach(() => {
+        fs.removeSync(rootFolderTmp);
+    });
+
+    test('test download extensions', async () => {
+        const expected = fs.readFileSync('tests/builtin-extensions/builtin-extensions')
+            .toString()
+            .split('\n')
+            .filter(value => !!value);
+
+        const builtinExtensions = new BuiltinExtensions(pluginsFolderTmp);
+        builtinExtensions['downloadExtension'] = jest.fn();
+        expect(await builtinExtensions.download()).toEqual(expected);
+    });
+
+});
diff --git a/generator/tests/init-sources/assembly-example/assembly-package.json b/generator/tests/init-sources/assembly-example/assembly-package.json
index c7bdc7ed0..bb78a1413 100644
--- a/generator/tests/init-sources/assembly-example/assembly-package.json
+++ b/generator/tests/init-sources/assembly-example/assembly-package.json
@@ -17,7 +17,6 @@
     "@theia/keymaps": "^0.3.16",
     "@theia/languages": "^0.3.16",
     "@theia/markers": "^0.3.16",
-    "@theia/merge-conflicts": "^0.3.16",
     "@theia/messages": "^0.3.16",
     "@theia/mini-browser": "^0.3.16",
     "@theia/monaco": "^0.3.16",
@@ -27,11 +26,9 @@
     "@theia/plugin-ext": "^0.3.16",
     "@theia/plugin-ext-vscode": "^0.3.16",
     "@theia/preferences": "^0.3.16",
-    "@theia/preview": "^0.3.16",
     "@theia/process": "^0.3.16",
     "@theia/search-in-workspace": "^0.3.16",
     "@theia/task": "^0.3.16",
-    "@theia/textmate-grammars": "^0.3.16",
     "@theia/tslint": "^0.3.16",
     "@theia/userstorage": "^0.3.16",
     "@theia/variable-resolver": "^0.3.16",
diff --git a/generator/tests/production/assembly/package.json b/generator/tests/production/assembly/package.json
index c7bdc7ed0..bb78a1413 100644
--- a/generator/tests/production/assembly/package.json
+++ b/generator/tests/production/assembly/package.json
@@ -17,7 +17,6 @@
     "@theia/keymaps": "^0.3.16",
     "@theia/languages": "^0.3.16",
     "@theia/markers": "^0.3.16",
-    "@theia/merge-conflicts": "^0.3.16",
     "@theia/messages": "^0.3.16",
     "@theia/mini-browser": "^0.3.16",
     "@theia/monaco": "^0.3.16",
@@ -27,11 +26,9 @@
     "@theia/plugin-ext": "^0.3.16",
     "@theia/plugin-ext-vscode": "^0.3.16",
     "@theia/preferences": "^0.3.16",
-    "@theia/preview": "^0.3.16",
     "@theia/process": "^0.3.16",
     "@theia/search-in-workspace": "^0.3.16",
     "@theia/task": "^0.3.16",
-    "@theia/textmate-grammars": "^0.3.16",
     "@theia/tslint": "^0.3.16",
     "@theia/userstorage": "^0.3.16",
     "@theia/variable-resolver": "^0.3.16",