Create a composer.json file:
{
"require-dev": {
"phpspec/phpspec": "~2.0"
},
"config": {
"bin-dir": "bin"
},
"autoload": {"psr-0": {"": "src"}}
}
Install phpspec with composer:
curl http://getcomposer.org/installer | php
php composer.phar install
Start writing specs:
bin/phpspec desc Acme/Calculator
Learn more from the documentation.