Drupal is free software used to run Web sites, and participants at the at the Polytechnic Institute of New York University in Downtown Brooklyn said they were drawn there, despite differences in backgrounds and ideologies, by a belief in an almost utopian form of technological cooperation. Drupal was developed by Dries Buytaert, a Belgian programmer, and nearly 10 years ago he made the Drupal code public, giving up formal control of his creation and letting people use it without charge with the stipulation that they share modifications and improvements with one another.