This project is not supported. Please take a look at http://drupal-composer.org/
This project is a small console application which generates packages.json files from projects on Drupal.org using the updates.drupal.org API.
The goal is to allow Drupal modules and themes to be used as dependencies in composer.json for Composer-based Drupal projects.
The project currently splits the packages.json file into multiple files using includes.
This is not optimal for the number of projects on Drupal.org which rivals the number of packages and versions on Packagist.
Instead the project should use provider-includes and providers-url.
This is work in progress. Consider it a prototype for now.