Before installing gulp and sass first you must have NodeJs installed, NodeJS will have npm (node packaged modules).

Node.js is a JavaScript runtime built on Chrome's V8 JavaScript engine. Node.js uses an event-driven, non-blocking I/O model that makes it lightweight and efficient. Node.js' package ecosystem, npm, is the largest ecosystem of open source libraries in the world.

Online Reference: https://nodejs.org/en/

Installing in Windows

Simply download the Windows Installer direct from the nodejs.org web site.

Installing in Mac

Simply download the Macintosh Installer direct from the nodejs.org web site.

If you want to download the package with bash:

curl "https://nodejs.org/dist/latest/node-${VERSION:-$(wget -qO- https://nodejs.org/dist/latest/ | sed -nE 's|.*>node-(.*)\.pkg.*|\1|p')}.pkg" > "$HOME/Downloads/node-latest.pkg" && sudo installer -store -pkg "$HOME/Downloads/node-latest.pkg" -target "/"

Using Homebrew:

brew install node

Before running grunt first you must check if you have sass installed in your machine. You can verify that sass is already installed by running the command.

$ sass --version

If version appear, it means sass already installed in your machine and proceed to the next topic, otherwise follow the instructions below on installing sass.

Installing in Windows

Before you start using Sass you will need to install Ruby. The fastest way to get Ruby on your Windows computer is to use Ruby Installer. It's a single-click installer that will get everything set up for you super fast.

Installing in Mac

If you prefer the command line over an application then getting Sass set up is a fairly quick process. Sass has a Ruby dependency but if you're using a Mac, congratulations, Ruby comes pre-installed.

Install SASS

Ruby uses Gems to manage its various packages of code like Sass. In your open terminal or cmd window:

$ gem install sass

You should now have Sass installed, but it never hurts to double-check.

$ sass --version

Online Reference: http://sass-lang.com/install

Before installing gulp first you must have NodeJs installed, NodeJS will have npm (node packaged modules).

Gulp is a toolkit for automating painful or time-consuming tasks in your development workflow, so you can stop messing around and build something.

Online Reference: https://gulpjs.com/

Installing the CLI

If you have previously installed a version of gulp globally, please run npm rm --global gulp to make sure your old version doesn't collide with gulp-cli.

$ npm install -g gulp-cli

Verify that gulp is successfully installed, and version of installed gulp will appear.

$ gulp --version

Start command prompt window or terminal and change directory to [getDuralux/html/webapps] folder and run following command to install all the "dependencies and devDependencies". It could take few minutes to complete installation.

$ npm install

This will take some time and install all necessary dependencies into the node_modules directory in order for you to start developing.

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Then start the development server on localhost:3000 use gulp

$ gulp

Runs the project locally, starts the development server and watches for any changes in your code, including your HTML, Javascript, sass, etc. The development server is accessible at http://localhost:3000.