Just an example to try out Composer create-project command
$ curl -s http://getcomposer.org/installer | php
$ php composer.phar create-project wdalmut/simple-mvc-app my-simple-mvc-project
In order to use Vagrant to run this app simple do
$ curl -s http://getcomposer.org/installer | php
$ php composer.phar install
$ git submodule init
$ git submodule update
$ vagrant up
When the VM is running you can go to your browser and type: http://localhost:8080/.
A simple This is the first title sentence should appear on your screen, if it appears
it means that Vagrant has configured the environment well (apache2/php5/mysql).