For Behat you need at least PHP 5.3.3 version installed on your system. No matter you install Behat on Window, Mac or Ubuntu, steps will remain same.There are 2 ways to install Behat on Your system:
Install Behat using composer: This is recommended and official way. Advantage of installing Behat using composer is that you can easily update to latest version later. Below are the steps:
Step 1. Create your project directory anywhere on your system
Step 2. Type below command
$ php composer.phar require --dev behat/behat
Step 3. Verify Version and Behat Installation
$ vendor/bin/behat -V
Install Behat using phar: This is easy way of installation but not recommended.
Step 1. Download the latest behat.phar from here Behat Git.
Step 2: Paste it to your project folder
Step 3: Type below command to verify the version and installation
php behat.phar -V